material from the ,google ,print project47 ,transcriber's ,notes ,in this ,plain ,text version1 ,greek cursive characters used in formulae are represented as alpha1 beta1 gamma1 lambda1 nu1 pi upsilon4 ,symbols for male and female are represented as male and female4 ,in chemical formulae1 the left arrow over right arrow symbol is represented by ,italic typeface has been represented by the use of underscores4 ,small capital typeface has been represented by the use of ,,all ,,capitals4 ,superscript characters are indicated by caret and braces1 e4g4 #aj-h 7ten to the power of minus eight74 ,subscript characters are indicated by underscore and braces1 e4g4 ,h#b,o4 ,uncommon forms for chemical names have been retained where they occur in the text1 e4g4 atropin for atropine2 asparagin for asparagine1 etc4 ,the spellings of ,sidot blend and ,sidot blende are used interchangeably in the text4 ,some inconsistencies in formatting and punctuation have been retained from the original4 ,,ph or ,p,h 7,p subscript ,h7 is retained as used in the text for the scale of alkali-acidity where the more familiar modern usage is p,h4 ,molar concentrations are indicated in various ways 7lower case m1 italic lower case m1 small capital ,m74 ,changes to the text have been made only in the case of obvious spelling or type-setting errors4 ,these are listed at the end of the book4 99 99 99 99 99 ,,monographs ,,on ,,experimental ,,biology ,,edited ,,by ,,jacques ,,loeb1 ,rockefeller ,institute ,t4 ,h4 ,,morgan1 ,columbia ,university ,w4 ,j4 ,v4 ,,osterhout1 ,harvard ,university ,,the ,,nature ,,of ,,animal ,,light ,,by ,e4 ,,newton ,,harvey1 ,ph4,d4 99 99 99 99 99 ,,monographs ,,on ,,experimental ,,biology ,,published ,,forced ,,movements1 ,,tropisms1 ,,and ,,animal ,,conduct ,by ,,jacques ,,loeb1 ,rockefeller ,institute ,,the ,,elementary ,,nervous ,,system ,by ,g4 ,h4 ,,parker1 ,harvard ,university ,,the ,,physical ,,basis ,,of ,,heredity ,by ,t4 ,h4 ,,morgan1 ,columbia ,university ,,inbreeding ,,and ,,outbreeding3 ,,their ,,genetic ,,and ,,sociological ,,significance ,by ,e4 ,m4 ,,east and ,d4 ,f4 ,,jones1 ,bussey ,institution1 ,harvard ,university ,,the ,,nature ,,of ,,animal ,,light ,by ,e4 ,n4 ,,harvey1 ,princeton ,university ,,in ,,preparation ,,pure ,,line ,,inheritance ,by ,h4 ,s4 ,,jennings1 ,johns ,hopkins ,university ,,the ,,experimental ,,modification ,,of ,,the ,,process ,,of ,,inheritance ,by ,r4 ,,pearl1 ,johns ,hopkins ,university ,,localization ,,of ,,morphogenetic ,,substances ,,in ,,the ,,egg ,by ,e4 ,g4 ,,conklin1 ,princeton ,university ,,tissue ,,culture ,by ,r4 ,g4 ,,harrison1 ,yale ,university ,,permeability ,,and ,,electrical ,,conductivity ,,of ,,living ,,tissue ,by ,w4 ,j4 ,v4 ,,osterhout1 ,harvard ,university ,,the ,,equilibrium ,,between ,,acids ,,and ,,bases ,,in ,,organism ,,and ,,environment ,by ,l4 ,j4 ,,henderson1 ,harvard ,university ,,chemical ,,basis ,,of ,,growth ,by ,t4 ,b4 ,,robertson1 ,university of ,toronto ,,coordination ,,in ,,locomotion ,by ,a4 ,r4 ,,moore1 ,rutgers ,college ,,others ,,will ,,follow 99 99 99 99 99 ,monographs on ,experimental ,biology ,,the ,,nature ,,of ,,animal ,,light ,,by ,e4 ,,newton ,,harvey1 ,ph4,d4 ,,professor ,,of ,,physiology1 ,,princeton ,,university ,illustration ,,philadelphia ,,and ,,london ,j4 ,b4 ,,lippincott ,,company ,,copyright1 #aibj4 ,,by ,j4 ,b4 ,,lippincott ,,company ,electrotyped and ,printed by ,j4 ,b4 ,lippincott ,company4 ,the ,washington ,square ,press1 ,philadelphia1 ,u4 ,s4 ,a4 ,,editors' ,,announcement ,the rapid increase of specialization makes it impossible for one author to cover satisfactorily the whole field of modern ,biology4 ,this situation1 which exists in all the sciences1 has induced ,english authors to issue series of monographs in ,biochemistry1 ,physiology1 and ,physics4 ,a number of ,american biologists have decided to provide the same opportunity for the study of ,experimental ,biology4 ,biology1 which not long ago was purely descriptive and speculative1 has begun to adopt the methods of the exact sciences1 recognizing that for permanent progress not only experiments are required but quantitative experiments4 ,it will be the purpose of this series of monographs to emphasize and further as much as possible this development of ,biology4 ,experimental ,biology and ,general ,physiology are one and the same science1 in method as well as content1 since both aim at explaining life from the physico-chemical constitution of living matter4 ,the series of monographs on ,experimental ,biology will therefore include the field of traditional ,general ,physiology4 ,,jacques ,,loeb1 ,t4 ,h4 ,,morgan1 ,w4 ,j4 ,v4 ,,osterhout4 ,,preface ,bioluminescence1 the production of light by animals and plants1 has always excited the admiration of the layman and the wonder of the scientist4 ,it is not surprising that an enormous literature dealing with the subject has grown up4 ,a large part of this literature1 however1 is made up merely of reports that a certain animal is luminous1 or records of especially brilliant phosphorescence of the sea4 ,among those who have inquired somewhat more carefully into the nature and causes of light production may be mentioned the names of ,beijerinck1 ,r4 ,boyle1 ,dahlgren1 ,dubois1 ,ehrenberg1 ,krukenberg1 ,mangold1 ,mc,dermott1 ,molisch1 ,panceri1 ,pflueger1 ,phipson1 ,quatrefages1 ,spallanzani1 and ,trojan4 ,several of these men have written comprehensive monographs on the subject4 ,it is not the purpose of this book to deal with every phase of bioluminescence4 ,volumes could be written on the evolutionary side of the problem and the structure and uses of luminous organs4 ,these questions can only be touched upon4 ,neither is it my purpose to discuss the ultimate cause of the light1 whether due to vibration of electrons or to other causes4 ,that problem must be left to the physicist1 although it is highly probable that a study of animal light will give important information regarding the nature of light in general1 and no theory of light can be adequate which fails to take into account the extraordinary powers of luminous animals4 ,we shall be concerned largely with the physical characteristics of animal light and the chemical processes underlying its production4 ,great advances have been made since the first early guesses that the light was due to phosphorus and was a kind of oxidation4 ,although the problem cannot be considered as solved1 it has been placed on a sound physico-chemical basis4 ,some material is oxidized4 ,exactly what this material is and why light accompanies its oxidation are the two more fundamental problems in the field of ,bioluminescence4 ,how far and with what success we have progressed toward a solution of these problems may be seen from a perusal of the following pages4 ,it gives me pleasure to acknowledge the kindness of ,dr4 ,w4 ,e4 ,forsythe of the ,nela ,institute1 ,cleveland1 ,ohio1 in reading and criticizing the manuscript of ,chapter ,,iii1 and of ,professor ,lyman of ,harvard ,university for a similar review of ,chapter ,,ii4 ,i am also deeply indebted to my wife for reading the proof and to ,dr4 ,jacques ,loeb and ,prof4 ,w4 ,j4 ,v4 ,osterhout for many suggestions throughout the book4 ,my thanks are also due to ,prof4 ,c4 ,ishikawa of the ,agricultural ,college1 ,imperial ,university of ,tokio1 ,japan1 for his generous assistance in providing ,cypridina material4 ,finally ,i wish to acknowledge the support of the ,carnegie ,institution of ,washington1 through its director of ,marine ,biology1 ,dr4 ,alfred ,g4 ,mayor4 ,without this support much of the work described in this book could not have been accomplished4 ,e4 ,n4 ,h4 ,,princeton1 ,n4 ,j41 ,october1 #aiai4 ,,contents ,,chapter ,,page ,i4 ,,light-,,producing ,,organisms #a ,early records and theories4 ,shining fish and flesh4 ,burning of the sea4 ,distribution of luminous organisms in plant and animal kingdoms4 ,secondary luminosity4 ,false luminosity4 ,st4 ,elmo's fire4 ,ignis fatuus4 ,flashing of flowers4 ,luminosity in man4 ,use to man of photogenic organisms4 ,,ii4 ,,luminescence ,,and ,,incandescence #bj ,the complete spectrum4 ,radiation and temperature4 ,cold light4 ,thermoluminescence4 ,phosphorescence and fluorescence4 ,triboluminescence and piezoluminescence4 ,crystalloluminescence4 ,chemiluminescence4 ,,iii4 ,,physical ,,nature ,,of ,,animal ,,light #dj ,purkinje phenomenon4 ,color and spectra of animal light4 ,polarization4 ,efficiency of animal light4 ,infra-red radiation4 ,ultra-violet radiation4 ,luminous efficiency and visual sensibility4 ,production of radiation penetrating opaque objects4 ,intensity of animal light4 ,summary4 ,,iv4 ,,structure ,,of ,,luminous ,,organs #fg ,photochemical and chemiphotic changes4 ,the eye and the luminous organ4 ,intracellular and extracellular luminescence4 ,continuous and intermittent luminescence4 ,periodicity of luminescence4 ,luminous bacteria4 ,noctiluca and photogenic granules4 ,chaetopterus and luminous gland cells4 ,cypridina4 ,luminous glands4 ,the firefly4 ,luminous organs 7photophores7 with lenses1 reflectors1 opaque and color screens4 ,uses and purpose of animal light4 ,v4 ,,the ,,chemistry ,,of ,,light ,,production1 ,,part ,i #he ,boyle's and ,spallanzani's experiments4 ,shining wood and burning coal4 ,oxygen and luminescence4 ,carbon dioxide and luminescence4 ,heat production during luminescence4 ,luminescence and respiration4 ,water and luminescence4 ,phipson's noctilucin4 ,luciferin and luciferase4 ,photogenin and photophelein4 ,proluciferin4 ,oxyluciferin4 ,pyrophorin or luciferescein4 ,chemiluminescent reactions4 ,biozymooxyluminescence4 ,,vi4 ,,the ,,chemistry ,,of ,,light ,,production1 ,,part ,,ii #aad ,pyrophorus luciferin and luciferase4 ,pholas luciferin and luciferase4 ,cypridina luciferin2 stability1 hydrolysis by acid and enzymes1 adsorption1 precipitation1 salting out1 solubility1 distribution4 ,cypridina luciferin a proteose8 ,cypridina luciferase and properties4 ,cypridina luciferase an albumin4 ,specificity of luciferase4 ,action of fat solvent anaesthetics4 ,action of cyanides4 ,oxyluciferin4 ,nature of oxidative reaction4 ,,vii4 ,,dynamics ,,of ,,luminescence #adc ,minute amounts of material for luminescence4 ,reaction velocity and chemiluminescence4 ,temperature and chemiluminescence4 ,oxidation in steps4 ,concentration and bioluminescence4 ,temperature and bioluminescence4 ,oxidation with and without luciferase4 ,reaction velocity and color of bioluminescence4 99 99 99 99 99 ,,the ,,nature ,,of ,,animal ,,light ,,chapter ,i ,,light-,,producing ,,organisms ,the fact that animals can produce light must have been recognized from the earliest times in countries where fireflies and glowworms abound1 but it is only since the perfection of the microscope that the phosphorescence of the sea1 the light of damp wood and of dead fish and flesh has been proved to be due to living organisms4 ,aristotle mentions the light of dead fish and flesh and both ,aristotle and ,pliny that of damp wood4 ,robert ,boyle in #affg made many experiments to show that the light from all three sources1 as well as that of the glowworm1 is dependent upon a plentiful supply of air and drew an interesting comparison between the light of shining wood and that of a glowing coal4 ,boyle had no means of finding out the true cause of the light and early views of its nature were indeed fantastic4 ,even as late as #ahjj ,hulme concludes from his experiments on phosphorescent fish that the light is a constituent principle of marine fishes and the first that escapes after the death of the fish4 ,it was only in #ahcj that ,michaelis suspected the light of dead fish to be the result of some living thing and in #ahed ,heller gave the name ,sarcina noctiluca to the suspected organism4 ,in #ahge ,pflueger showed that nutrient media could be inoculated with small amounts of luminous fish and that these would increase in size1 like bacterial colonies1 and we now know that the light of all dead fish and flesh is due to luminous bacteria4 ,in the early part of the nineteenth century it was surmised that the light of damp wood was connected with fungus growth because of a similarity in smell4 ,in #ahed ,heller recognized minute strands1 which he called ,rhizomorpha noctiluca1 as the actual source of the light4 ,we now know that all phosphorescent wood is due to the mycelium of various kinds of fungi and that sometimes the fruiting body of the fungus also produces light4 ,the phosphorescence or burning of the sea1 which is described by so many of the older explorers1 is also due entirely to living organisms1 both microscopic and macroscopic4 ,the latter are mostly jelly-fish 7medusae7 or comb jellies 7,ctenophores7 and give rise to the larger1 more brilliant flashes of light often seen in the wake or about the sides of a steamer at night4 ,the former are various species of dinoflagellates or cystoflagellates such as ,noctiluca 7just visible to the naked eye7 which collect at the surface of the sea and often increase in such numbers that the water is colored by day 7usually pink or red7 and shines like a sheet of fire when disturbed at night4 ,although ,noctiluca was recognized as a luminous animal in #agec by ,baker1 the light of the sea was a mysterious phenomenon to the older observers4 ,mac,cartney1 speaking before the ,royal ,society in #ahaj1 outlines the various older theories as follows3 ,many writers have ascribed the light of the sea to other causes than luminous animals4 ,martin supposed it to be occasioned by putrefaction2 ,silberschlag believed it to be phosphoric2 ,prof4 ,j4 ,mayer conjectured that the surface of the sea imbibed light1 which it afterwards discharged4 ,bajon and ,gentil thought the light of the sea was electric1 because it was excited by friction4444 ,i shall not trespass on the time of the ,society to refute the above speculations2 their authors have left them unsupported by either arguments or experiments1 and they are inconsistent with all ascertained facts upon the subject4 ,the remarkable property of emitting light during life is only met amongst animals of the four last classes of modern naturalists1 viz41 mollusca1 insects1 worms1 and zoophytes4 ,mac,cartney recognized the true cause of the light1 although he had little idea of the vast number of marine forms which are luminous and omits entirely any reference to the fishes1 many of which produce a light of their own when living1 apart from any bacterial infection4 ,a survey of the animal kingdom discloses at least #cf orders containing one or more forms known to produce light and several more orders containing species whose luminosity is doubtful4 ,in the plant kingdom there are two groups containing luminous forms4 ,the distribution of luminous organisms is brought out in the accompanying classification of plants and animals4 ,those orders are printed in italics which contain species whose self-luminosity is fairly well established4 ,it will be noted that further subdivisions into orders is not given in classes of animals which lack luminous forms4 ,,table ,i ,,distribution ,,of ,,luminous ,,organisms ,,in ,,plant ,,and ,,animal ,,kingdoms ,,plant ,,kingdom ,i4 ,thallophyta ,algae ,cyanophyceae 7,blue-green ,algae7 ,chlorophyceae 7,green ,algae7 ,phaeophyceae 7,brown ,algae7 ,rhodophyceae 7,red ,algae7 ,lichenes 7,lichens1 symbiotic growth of algae and fungi7 ,fungi ,myxomycetes 7,slime moulds7 ,schizomycetes 7,bacteria7 ,bacterium1 ,photobacterium1 ,bacillus1 ,pseudomonas1 ,micrococcus1 ,microspira1 ,vibrio4 ,phycomycetes 7moulds7 ,ascomycetes 7,sac fungi1 yeasts1 some moulds7 ,basidiomycetes 7,smuts1 rusts1 mushrooms7 ,ustilaginae 7,smuts7 ,uridineae ,auriculariae 7,judas ears7 ,tremellineae 7,jelly fungi7 ,hymenomycetes 7,mushrooms7 ,agaricus1 ,armillaria1 ,pleurotus1 ,panus1 ,mycena1 ,omphalia1 ,locellina1 ,marasinium1 ,clitocybe1 ,corticium4 ,gasteromycetes 7,stinkhorns and puff-balls7 ,,ii4 ,bryophyta ,hepaticae 7,liverworts7 ,musci 7,mosses7 ,,iii4 ,pteridophyta ,equisetineae 7,horsetails7 ,salviniae 7,salvinia1 ,marsilia1 etc47 ,lycopodineae 7,club ,mosses7 ,filicineae 7,ferns7 ,,iv4 ,spermatophyta ,gymnospermae 7,cycads1 ,ginkgo1 ,conifers7 ,angiospermae 7,mono- and ,dicotyledonous flowering plants74 ,,animal ,,kingdom ,i4 ,protozoa4 7,one-celled animals7 ,sarcodina ,rhizopoda ,heliozoa ,radiolaria ,thallassicola1 ,myxosphaera1 ,collosphaera1 ,collozoum1 ,sphaerozoum4 ,mastigophora ,flagellata ,choanoflagellata ,dinoflagellata ,ceratium1 ,peridinium1 ,prorocentrum1 ,pyrodinium1 ,gonyaulax1 ,blepharocysta1 ,amphidinium1 ,diplopsalis1 ,cochlodinium1 ,sphaerodinium1 ,gymnodinium4 ,cystoflagellata ,noctiluca1 ,pyrocystis1 ,leptodiscus1 ,craspedotella4 ,sporozoa ,infusoria ,,ii4 ,porifera 7,sponges7 ,calcarea ,hexactinellida ,desmospongiae ,,iii4 ,coelenterata ,hydrozoa 7,hydroids and ,jelly-fish7 ,leptomedusae or ,campanulariae ,medusa form--,eutima1 ,phyalidium 7,oceania74 ,hydroid form--,aglaophenia1 ,campanularia1 ,sertularia1 ,plumularia1 ,cellularia1 ,valkeria1 ,obelia1 ,clytia4 ,trachomedusae ,geryonia1 ,lyriope1 ,aglaura ,narcomedusae ,cunina ,anthomedusae or ,tubulariae ,medusa form--,thaumantias1 ,tiara1 ,turris1 ,sarsia4 ,hydroid form--8 ,hydrocorallinae ,siphonophora ,abyla1 ,praya1 ,diphyes1 ,eudoxia1 ,hippopodius4 ,scyphozoa 7,jelly-fish7 ,stauromedusae ,peromedusae ,cubomedusae ,carybdia ,discomedusae ,pelagia1 ,aurelia1 ,chrysaora1 ,rhizostoma1 ,cyanaea1 ,dianea1 ,mesonema4 ,actinozoa 7,corals1 ,sea-fans1 ,sea-pens1 ,sea-anemones7 ,actinaria ,madreporareia ,antipatharia ,alcyonaria ,alcyonium1 ,gorgonia1 ,isis1 ,mopsea ,pennatulacea ,pennatula1 ,pteroides1 ,veretillum1 ,cavernularia4 ,funicularia1 ,renilla1 ,pavonaria1 ,stylobelemon1 ,umbellularia1 ,virgularia8 ,ctenophora 7,comb-jellies7 ,cydippida ,pleurobranchia4 ,lobata ,mnemiopsis1 ,bolinopsis1 ,leucothea 7,eucharis74 ,cestida ,cestus4 ,beroida ,beroe4 ,,iv4 ,platyhelminthes ,turbellaria 7,flat-worms7 ,trematodes 7,parasitic flat-worms7 ,cestodes 7,tape-worms7 ,nemertinea 7,nemertines7 ,v4 ,nemathelminthes ,nematoda 7,round worms7 ,gordiacea 7,hair worms7 ,acanthocephala 7,acanthocephalids7 ,chaetognatha 7,sagitta7 ,,vi4 ,trochelminthes ,rotifera 7,wheel animalcules7 ,gastrotricha 7,chaetonotus7 ,kinorhyncha 7,echinoderes7 ,,vii4 ,molluscoidea ,bryozoa 7,corallines7 ,entoprocta ,ectoprocta ,membranipora1 ,scrupocellaria1 ,retepora8 ,flustra8 ,brachiopoda 7,lamp shells7 ,phoronidea 7,phoronis7 ,,viii4 ,annulata ,archiannelida 7,primitive worms1 including ,dinophilus7 ,chaetopoda 7,true worms7 ,polychaeta ,chaetopterus1 ,phyllochaetopterus1 ,telepsaris1 ,polynoe1 ,acholoe1 ,tomopteris1 ,odontosyllis1 ,lepidonotus1 ,pionosyllis1 ,phyllodoce1 ,heterocirrus1 ,polyopthalamus8 ,oligochaeta ,lumbricus1 ,photodrilus1 ,allolobophora 7,eisemia71 ,microscolex1 ,nonlea1 ,enchytraeus1 ,octochaetus4 ,gephyrea 7,sipunculus7 ,hirudinea 7,leeches7 ,myzostomida 7,myzostomus7 ,,ix4 ,echinodermata ,asteroidea 7,star-fish7 ,ophiuroidea 7,brittle-stars7 ,ophiurida ,ophiopsila1 ,amphiura1 ,ophiacantha1 ,ophiothrix1 ,ophionereis4 ,euryalida ,echinoidea 7,sea urchins7 ,holothuroidea 7,sea ,cucumbers7 ,crinoidea 7,feather-stars7 ,x4 ,arthropoda ,crustacea 7,crabs1 lobsters1 shrimps1 etc47 ,phyllapoda ,ostracoda ,halocypris1 ,cypridina1 ,pyrocypris1 ,conchoecia1 ,cyclopina4 ,copepoda ,metridia1 ,leuckartia1 ,pleuromma1 ,oncaea1 ,heterochaeta4 ,cirripedia ,phyllocardia ,schizopoda ,nyctiphanes1 ,nematoscelis1 ,gnathophausia1 ,euphausia1 ,stylochiron1 ,boreophausia1 ,mysis8 ,decapoda ,sergestes1 ,aristeus1 ,heterocarpus1 ,hoplophorus1 ,acanthephyra1 ,pentacheles1 ,colossendeis ,stomatopoda ,cumacea ,amphipoda ,isopoda ,onychophora 7,peripatus7 ,myriapoda 7,centipedes and ,millepedes7 ,symphyla ,chilopoda ,geophilus1 ,scolioplanes1 ,orya4 ,diplopoda ,pauropoda ,insecta 7,insects7 ,aptera 7,spring-tails7 ,lipura1 ,amphorura1 ,neanura ,orthoptera ,neuroptera ,teleganoides and ,caenis of the ,mayflies8 ,termites8 ,hemiptera ,diptera 7,flies7 ,bolitophila and ,ceroplatus larvae1 ,thyreophora8 ,coleoptera 7,beetles7 ,pyrophorus1 ,photophorus1 ,luciola1 ,lampyris1 ,phengodes1 ,photuris1 ,photinus1 etc4 ,lepidoptera ,hymenoptera ,arachnida 7,spiders7 ,,xi4 ,mollusca ,amphineura 7,chiton7 ,pelecypoda 7,bivalves7 ,protobranchia ,filibranchia ,pseudo-,lamellibranchia ,eu-lamellibranchia ,pholas ,septibranchiata ,gasteropoda 7,snails1 periwinkles1 slugs1 etc47 ,prosobranchiata ,ophisthobranchiata ,phyllirrhoe1 ,plocamopherus4 ,pulmonata ,scaphopoda 7,dentalium7 ,cephalopoda 7,squids and ,octopus7 ,tetrabranchiata ,dibranchiata decapoda ,onychoteuthis1 ,chaunoteuthis1 ,lycoteuthis1 ,nematolampas1 ,lampadioteuthis1 ,enoploteuthis1 ,abralia1 ,abraliopsis1 ,watasenia1 ,ancistrocheirus1 ,thelidioteuthis1 ,pterygioteuthis1 ,pyroteuthis1 ,octopodoteuthis81 ,calliteuthis1 ,histioteuthis1 ,benthoteuthis1 ,hyaloteuthis1 ,eucleoteuthis1 ,chiroteuthis1 ,mastigoteuthis1 ,cranchia1 ,liocranchia1 ,pyrgopsis1 ,leachia1 ,liguriella1 ,phasmatopsis1 ,toxeuma1 ,megalocranchia1 ,leucocranchia1 ,crystalloteuthis1 ,phasmatoteuthis1 ,galiteuthis1 ,corynomma1 ,hensenioteuthis1 ,bathothauma1 ,rossia81 ,heteroteuthis1 ,iridoteuthis1 ,sepiola1 ,rondeletia1 ,inioteuthis1 ,euprymna1 ,melanoteuthis84 ,,xii4 ,chordata ,adelochorda 7,balanoglossus7 ,balanoglossus1 ,ptychodera1 ,glossobalanus ,urochorda 7,ascidians7 ,larvacea ,appendicularia8 ,thaliacea ,salpa1 ,doliolum8 ,ascidiacea ,pyrosoma1 ,phallusia ,acrania 7,amphioxus7 ,cyclostomata 7,cylostomes7 ,pisces 7,fishes7 ,elasmobranchii ,centroscyllium1 ,spinax1 ,paracentroscyllium1 ,isistius1 ,laemargus1 ,euproctomicrus1 ,benthobatis8 ,holocephalii ,dipnoi ,teleostomi ,stomias1 ,chauliodus1 ,melanostomius1 ,pachystomias1 ,bathophilus1 ,dactylostomius1 ,malacosteus1 ,astronesthes1 ,ophozstomias1 ,idiacanthus1 ,bathylychnus1 ,macrostomius1 ,gonostoma1 ,cyclothone1 ,photichthys1 ,vinciguerria1 ,ichthyococcus1 ,lychnopoles1 ,diplophos1 ,triplophos1 ,valenciennellus1 ,maurolicus1 ,argyropelecus1 ,sternoptyx1 ,polyipnus1 ,ipnops8 ,neoscopelus1 ,myctophum1 ,halosausus1 ,xenodermichthys8 ,macrurus8 ,photoblepharon1 ,anomalops1 ,porichthys1 ,leuciocornus1 ,mixonus8 ,bassozetus8 ,oneirodes1 ,ceratias1 ,gigantactis1 ,chaunax1 ,malthopsis1 ,halicmetus1 ,monocentris1 ,lamprogrammus4 ,amphibia 7,frogs1 ,toads1 ,salamanders7 ,reptilia 7,snakes1 ,lizards1 ,turtles7 ,aves 7,birds7 ,mammalia 7,mammals7 ,the only groups of the plant kingdom which are known to produce light are some of the bacteria and some of the fungi and the dinoflagellates 7,peridineae7 if one is to include them among the plants4 ,many different species of phosphorescent bacteria have been described1 differing in cultural characteristics and structural peculiarities and grouped in the genera1 ,bacterium1 ,photobacterium1 ,bacillus1 ,microspira1 ,pseudomonas1 ,micrococcus1 and ,vibrio4 ,specific names indicating their light-producing power such as phosphorescens1 phosphoreum1 luminosum1 lucifera1 etc41 have been applied4 ,all the fungi which are definitely known to produce light belong to the ,basidiomycetes1 the largest and most highly developed of the true fungi4 ,either the mycelium alone or the fruiting body alone1 or both1 may be luminescent4 ,among animals the best known forms are the dinoflagellates2 ,noctiluca2 hydroids2 jelly-fish2 ctenophores2 sea pens2 ,chaetopterus and other marine worms2 earthworms2 brittle stars2 various crustaceans2 myriapods2 fireflies and glowworms1 the larvae of fireflies2 ,pholas dactylus and ,phyllirrhoe bucephala1 both molluscs2 squid2 ,pyrosoma1 a colonial ascidian2 and fishes4 ,luminous animals are all either marine or terrestrial forms4 ,no examples of fresh water luminous organisms are known4 ,of marine forms1 the great majority are deep sea animals1 and it is among these that the development of true luminous organs of a complicated nature is most pronounced4 ,many of the luminous marine animals are to be found in the plankton1 while the littoral luminous forms are in the minority4 ,some members of all the above groups are found at one or another of our marine laboratories with the possible exception of ,pholas1 ,phyllirrhoe and squid4 ,although earthworms and myriapods which produce light are found in the ,united ,states1 they are rather rare and seldom observed forms4 ,not only adult forms but the embryos and even the eggs of some animals are luminous4 ,the egg of ,lampyris emits light within the ovary and freshly laid eggs are quite luminous4 ,the light does not come from luminous material of the luminous organ adhering to the egg when it is laid but from within the egg itself4 ,pyrophorus eggs are also luminous4 ,the segmentation stages of ,ctenophores are luminous on stimulation1 as noted by ,allman 7#ahfb71 ,agassiz 7#ahgd7 and ,peters 7#aije71 but the eggs themselves do not luminesce4 ,schizopod larvae 7,trojan1 #aijg71 ,copepod nauplii 7,giesbrecht1 #ahie71 ,chaetopterus larvae 7,enders1 #aiji71 and brittle star plutei 7,mangold1 #aijg7 also produce light4 ,apparently there is no rhyme or reason in the distribution of luminescence throughout the plant or animal kingdom4 ,it is as if the various groups had been written on a blackboard and a handful of sand cast over the names4 ,where each grain of sand strikes1 a luminous species appears4 ,the ,coelenterates have received most sand4 ,luminescence is more widespread in this phylum and more characteristic of the group as a whole than any other4 ,among the arthropods luminous forms crop up here and there in widely unrelated groups4 ,in the mollusks1 excluding the cephalopods1 only two luminous species are known4 ,several phyla contain no luminous forms whatever4 ,it is an extraordinary fact that one species in a genus may be luminous and another closely allied species contain no trace of luminosity4 ,there seems to have been no development of luminosity along direct evolutionary lines1 although a more or less definite series of gradations with increasing structural complexity may be traced out among the forms with highly developed luminous organs4 ,while the accompanying list of luminous genera aims to be fairly complete1 there are no doubt omissions and some inaccuracies in it4 ,anyone who has ever tried to determine what animal is responsible for the occasional flashes of light observed on agitating almost any sample of sea water will realize how difficult it is to discover the luminous form among a host of non-luminous ones1 especially if the animal is microscopic in size4 ,it is not surprising1 then1 to find many false reports of luminous animals in the literature of the subject and we cannot be too careful in accepting as luminous a reported case4 ,the difficulty lies chiefly in the fact that all luminous organisms with the exception of bacteria1 fungi1 and a few fish1 flash only on stimulation1 and1 while it is easy enough to see the flash1 the animal is lost between the flashes4 ,the only safe way to detect luminous organisms is to add a little ammonia to the sea water4 ,this slowly kills the organisms and causes any luminous forms to glow with a steady1 continuous light for some time1 a condition accompanying the death of the animal4 ,not all observers1 however1 have followed this method4 ,one must always be on guard against confusing the light from a supposed luminous form with the light from truly luminous organisms living upon it4 ,the reported cases of luminosity among marine algae are now known to be due to hydroids or unicellular organisms living on the alga4 ,we know also that many non-luminous forms may become infected with luminous bacteria1 not only after death1 but also while living1 so that their luminescence is purely secondary4 ,giard and ,billet 7#ahhi-ij7 succeeded in inoculating many different kinds of amphipod crustacea 7,talitrus1 ,orchestia1 ,ligia7 and isopod crustacea 7,porcellio1 ,philoscia7 with luminous bacteria1 in some cases passing the infection from one to the next through nine individuals4 ,curiously enough the bacterium did not produce light on artificial culture media but did when growing in the body of the crustacea1 which were killed in about seven days by the infection4 ,the species of ,talitrus and ,orchestia might easily have been taken for truly luminous animals if not carefully investigated4 ,tarchanoff 7#aija7 has injected luminous bacteria into the dorsal lymph sac of frogs with the result that the animals continued to glow for three to four days1 especially about the tongue4 ,i remember once while collecting luminous beetles in ,cuba1 ,i was astounded to find a frog which was luminous4 ,expecting this animal to be of great interest1 ,i examined it further only to find that the frog had just finished a hearty meal of fireflies1 whose light was shining through the belly with considerable intensity4 ,infection with luminous bacteria is especially liable to occur in any dead marine animal4 ,the flesh is an excellent culture medium4 ,i have seen non-luminous species of squid1 recently killed1 covered with minute growing colonies1 quite evenly spaced1 so as to closely resemble luminous species whose light is restricted to scattered light organs over the surface of the body4 ,indeed ,pierantoni 7#aiah7 has carried this idea to extremes4 ,he believes that in the luminous organs of fireflies1 cephalopods and ,pyrosoma1 luminous symbiotic bacteria occur which are responsible for the light of these animals1 and he claims in the case of cephalopods and ,pyrosoma to have been able to isolate these in pure culture on artificial culture media4 ,in the firefly they can be seen but not grown and in luminous animals where no visible bacteria-like structures are apparent he believes we are dealing with ultra-microscopic luminous bacteria similar to the pathogenic forms suspected in filterable viruses4 ,while the assumption of ultra-microscopic organisms makes the refutation of ,pierantoni's views a somewhat hazardous task1 no one can deny that even an ultra-microscopic organism will be killed by boiling with #bj per cent4 7by wt47 ,h,cl for #f hours4 ,as we shall see1 the luminous material of ,cypridina1 an ostracod crustacean1 can withstand such prolonged boiling with strong acid4 ,the light of one animal at least1 and ,i believe many others also1 cannot be due to any sort of symbiotic organism4 ,apart from these cases where light is actually produced but is not primary1 not produced by the animal itself1 there are many forms whose surface is so constituted as to produce interference colors4 ,this is true in many cases among the birds and butterflies whose feathers and scales are iridescent4 ,some of these have been erroneously described as luminous4 ,perhaps the best known case among aquatic animals is ,sapphirina1 a marine copepod living at the surface of the sea1 and especially likely to be collected with other luminous forms4 ,its cuticle is so ruled with fine lines as to diffract the light and flash on moving much as a fire opal4 ,needless to say no trace of light is given off from this animal in a totally dark room4 ,it has often been supposed that the eye of a cat or of other animals is luminous4 ,the eyes of a moth1 also1 can be seen to glow like beads of fire when it is flying about a flame4 ,both of these cases are1 however1 purely reflection phenomena and due to reflection out of the eye again of light which has entered from some external source4 ,the correct explanation was given by ,prevost in #ahaj4 ,the eye of any animal is quite invisible in absolute darkness4 ,the same explanation applies to the moss1 ,schistostega1 which lives in dimly illuminated places and whose cells are almost spherical1 constructed like a lens1 so as to refract the light and condense it on the chloroplasts at the bottom of the cells4 ,some of this light is reflected out of the cells again and gives the appearance of self-luminosity4 ,the alga1 ,chromophyton rosanoffii1 is another example of apparent luminosity1 due to reflection from almost spherical cells4 ,there are several light phenomena known which have nothing to do with living organisms4 ,commonest of these is ,st4 ,elmo's fire 7corposants of ,english sailors71 a glow accompanying a slow brush discharge of electricity1 which appears as a tip of light on masts of ships1 spires of churches or even the fingers of the hand4 ,it is best seen in winter during and after snowstorms and is a purely electrical phenomenon4 ,less well known is the ,ignis fatuus 7,will-o'-the-,wisp1 ,jack-o'-,lantern1 spunkie71 a fire seen over marshes and stagnant pools1 appearing as a pale bluish flame which may be fixed or move1 steady or intermittent4 ,so uncommon is this phenomenon that its nature is not well understood1 but it is believed to be the result of burning phosphine 7,,ph#c ,p#b;,h#d71 a self-inflammable gas1 generated in some way from the decomposition of organic matter in the swamp4 ,the difficulty with this explanation is that phosphine is not known as a decomposition product of organized matter4 ,methane 7,,ch#d71 a well-known decomposition product of organic matter and abundantly formed in swamps1 will burn with a pale bluish flame and some have thought the ,ignis fatuus to be the result of this gas4 ,as methane is not self-inflammable there remains the difficulty of explaining how it becomes lighted4 ,although still a mystery1 it is possible that this light is also of electrical origin or that in some cases large clusters of luminous fungi have been observed4 ,the flashing of flowers1 especially those of a red or orange color1 like the poppy1 which many observers have noticed during twilight hours1 is a purely subjective phenomenon due to the formation of after images in eyes partially adapted to the dark4 ,this flashing1 first observed by the daughter of ,linnaeus1 is never observed in total darkness or in the direct field of vision1 but only in the indirect field as during a sidelong glance at the plant4 ,there are some cases of luminosity on record in connection with man himself4 7,see ,heller1 #ahed74 ,before the days of aseptic and antiseptic surgery1 wounds frequently became infected with luminous bacteria and glowed at night4 ,the older surgeons even supposed that luminous wounds were more apt to heal properly than non-luminous ones4 ,we know that luminous bacteria are non-pathogenic1 harmless organisms and the presence of these forms even on dead fish or flesh never accompanies but always precedes putrefaction4 ,as recorded by ,robert ,boyle1 no harm has come from eating luminous meat1 unless it may also have become infected with pathogenic forms4 ,a few cases of luminous individuals have been noted in which the skin was the source of light1 especially if the person sweated freely4 ,it is possible that here we are again dealing with luminous bacteria upon the accumulations of substances passed out in the sweat1 which serves as a nutrient medium4 ,there are also on record1 in the older literature1 cases of luminous urine1 where the urine when freshly voided was luminous4 ,if these observations are correct and they may1 perhaps1 be doubted1 we are at present uncertain of the cause of the light4 ,bacterial infections of the bladder are not inconceivable although luminous bacteria are strongly aerobic and would not thrive under anaerobic conditions4 ,i can state from my own experiments that luminous bacteria will live in normal human urine1 but not well4 ,in albuminous urines it is very likely that they would live better1 and it is possible that the luminous urines reported are the results of luminous bacterial infection4 ,on the other hand1 the light may be purely chemical1 due to the oxidation of some compound1 an abnormal incompletely oxidized product of metabolism1 which oxidizes spontaneously in the air4 ,we know that sometimes these errors in metabolism occur1 as in alkaptonuria1 where homogentistic acid is excreted in the urine and on contact with the air quickly oxidizes to a dark brown substance4 ,light1 however1 has never been reported to accompany the oxidation of homogentistic acid1 although it does accompany the oxidation of some other organic compounds4 7,see ,chapter ,,ii47 ,finally1 we may inquire to what extent luminous animals may be utilized by man4 ,leaving out of account the use of tropical fireflies for adornment by the natives of the ,west ,indies and ,south ,america and the use for bait1 in fishing1 of the luminous organ of a fish1 ,photoblepharon1 by the ,banda islanders1 we find that luminous bacteria are of value for certain purposes in the laboratory4 ,these methods are all due to ,beijerinck 7#ahhi1 #aijb74 ,he has1 for instance1 used luminous bacteria for testing bacterial filters4 ,if there is a crack in the filter the bacteria will pass through and a luminous filtrate is the result1 but a perfect filter allows no organisms to pass and gives a dark filtrate4 ,luminous bacteria are also very sensitive to oxygen and cease to luminesce in its absence4 ,by mixing luminous bacteria with an emulsion of chloroplasts 7from clover leaves7 in the dark1 allowing the bacteria to use up all the oxygen1 and then exposing the mixture to light of various colors1 the effect of different wave-lengths in causing photosynthesis could be studied4 ,only if the chloroplasts are exposed to a color in the spectrum which decomposes ,,co#b with liberation of oxygen do the bacteria luminesce1 and when this oxygen is used up by the bacteria1 the tube again becomes dark4 ,beijerinck has also worked out a method of testing for maltose and diastase with luminous bacteria1 based on the fact that a certain form1 ,photobacterium phosphorescens1 will only produce light in presence of maltose or diastase which will form maltose from starch4 ,although ,dubois and ,molisch have both prepared bacterial lamps and although it has been suggested that this method of illumination might be of value in powder magazines where any sort of flame is too dangerous1 it seems doubtful1 to say the least1 whether luminous bacteria can ever be used for illumination4 ,other forms1 perhaps1 might be utilized1 but bacteria produce too weak a light for any practical purposes4 ,the history of ,science teaches that it is well never to say that anything is impossible4 ,it is very unlikely that any luminous animal can be utilized for practical illumination1 but there is no reason why we cannot learn the method of the firefly4 ,then we may1 perhaps1 go one step further and develop a really efficient light along similar lines4 ,to what extent our inquiry into the secret of the firefly has been successful may be gleaned from the following pages4 ,,chapter ,,ii ,,luminescence ,,and ,,incandescence ,modern physical theory supposes that light is a succession of wave pulses in the ether caused by vibrating electrons4 ,the light to which we are most accustomed--sunlight1 electric light1 gaslight1 etc41--is due to electrical phenomena connected more or less directly with the high temperature of the source of the light4 ,every solid body above the temperature of absolute zero is giving off waves of different wave-length 7lambda7 and frequency 7nu7 but of the same velocity 7upsilon71 in vacuo1 #ahj1jjj miles1 or #cjj1jjj kilometres a second4 ,in fact1 upsilon 7a constant7lambdanu1 so that it is only necessary to designate the wave-length in order to characterize the waves4 ,this is radiant energy or radiant flux4 ,as everyone knows1 the long waves given off in largest amount from objects at comparatively low temperatures give the sensation of warmth4 ,as we raise the temperature1 in addition to these longer heat waves1 those of shorter and shorter wave-length are given off in sufficient quantity to be detected4 ,at #ebe deg4 ,c41 rays of about lambda4#gf mu in length are just visible as a faint red glow to the eye4 ,as the temperature increases still shorter wave-lengths become apparent1 and the light changes to dark red 7#gjj deg471 cherry red 7#ijj deg471 dark yellow 7#aajj deg471 bright yellow 7#abjj deg471 white-hot 7#acjj deg47 and blue-white 7#adjj deg4 and above74 ,above lambda4#d mu the waves again fail to affect our eye1 and1 although they are very active in producing chemical changes1 we have no sense organs for perceiving them4 ,thus1 a white-hot object liberates radiant energy or flux of many different wave-lengths corresponding to what we know as heat1 light and actinic rays4 ,all can be dispersed by prisms of one or another appropriate material to form a wide continuous spectrum1 such as that indicated in ,fig4 #a4 ,radiant energy of lambda4#gf mu to lambda4#d mu1 evaluated according to its capacity to produce the sensation of light1 is spoken of as visible radiation or luminous flux4 ,below the infra-red comes a region of wave-length as yet uninvestigated1 and beyond this may be placed the ,hertzian electric waves of long wave-length used in wireless telegraphy4 ,above the ultra-violet comes another region as yet uninvestigated1 and then ,roentgen rays 7,x-rays7 and radium rays1 of exceedingly short wave-length4 ,these last types need not concern us except in that we may later inquire if they are given off by luminous animals4 ,the shortest of the ultra-violet are known as ,schumann and ,lyman rays4 ,these relations are brought out in ,table #b4 ,,table #b4 ,wave-lengths of ,various ,kinds of ,radiation ,wave-lengths of light are usually given in ,angstrom units4 ,one micron 7 mu74#jja mm4#ajjj millimicrons 7 mu mu7#aj1jjj ,angstrom units 7,a7 or tenth metres#aj-aj metres or #aj-h centimetres4 ,the entire scale of wave-lengths extends from #ajf to #aj-i centimetres4 ,hertzian electric waves 7upper limit not reached7 above #ab km4 to 4#af cm4 ,unexplored region 4#af cm4 to #caj mu ,infra-red #caj mu to 4#gf mu ,visible light #gfjj ,a to #djjj ,a ,ultra-violet #djjj ,a to #cbj ,a ,unexplored region #cbj ,a to #ab ,a ,x-rays #ab ,a to #j4b ,a ,radium gamma rays #j4b ,a and shorter ,illustration3 ,,fig4 #a4--,schematic representation of various types of radiation to form a wide continuous spectrum4 4#je;,a 4#b;,a 4#h #c4b #ab4h #ej4 #bjj4 #hjj4 #cbjj4 #a4bh mu ---------------------------------------- ------------- 444 ,,radium gamma ,x ,,rays ,,unexplored ,,ultraviolet ,,visible ,,rays ---------------------------------------- ------------- 444 #a4bh mu #e4 mu #bj4 #hj4 #cbj4 4#abh;cm4 4#e;cm4 444 --------------------------------------- ,,hertzian ,,infra ,,red ,,unexplored ,,electric ,,waves 444 --------------------------------------- ,the total radiant energy which a body emits is a function of its temperature and for a perfect radiator1 or what is known as a black body1 the total radiation varies as the fourth power of the absolute temperature1 ,t4 7,stefan-,boltzmann ,law74 ,the radiant energy emitted at different wave-lengths is not the same but more energy is emitted at one particular wave-length 7lambdamax47 than at longer or shorter ones1 depending also on the temperature4 ,if the various waves are intercepted in some way1 their relative energy can be measured by an appropriate instrument and spectral energy curves can be drawn1 showing the distribution of energy throughout the spectrum4 ,fig4 #b gives a few of the curves1 and it will be noted that the maximum shifts toward the shorter waves the higher the temperature4 ,in fact1 for a black body lambdamax4x,t#bhij1 and at #ejjj deg4 ,c4 7about the temperature of the sun7 lambdamax4 lies within the visible spectrum4 ,in gas or electric lights it lies in the infra-red region4 ,the area enclosed by these spectral energy curves represents the total energy emitted1 and1 knowing this and the area enclosed by the curve of visible radiation1 it is easy to determine how efficient a source of light is as a light-producing body4 ,we shall inquire more fully into this question in ,chapter ,,iii1 in considering the efficiency of the firefly as a source of light4 ,illustration3 ,,fig4 #b4--;,distribution of energy throughout the spectrum of the sun1 electric arc1 and gas light 7after ,nichols and ,franklin74 ,ordinates show the relative intensities of different wave-lengths emitted4 ,the notches in the curve represent absorption bands and the dotted line represents what the radiation from the sun would be if no selective absorption occurred4 ,vviolet and ,rred end of visible spectrum4 7,courtesy ,macmillan ,co47 ,a body which emits light because of its 7high7 temperature is said to be incandescent and we speak of temperature radiation4 ,we know1 however1 of many cases where substances give off light at temperatures much below #ebe deg4 ,c4 ,they do not follow the ,stefan-,boltzmann law4 ,the light emission is stimulated by some other means than heat4 ,such bodies we speak of as luminescent1 and in this category belong all luminous animals4 ,the distinction between light and luminescence was first pointed out by ,wiedemann 7#ahhh74 ,it is usual to classify luminescences1 according to the means of exciting the light1 into the following groups3 ,thermoluminescence ,phosphorescence and ,fluorescence ,photoluminescence ,cathodoluminescence ,anodoluminescence ,radioluminescence ,triboluminescence and ,piezoluminescence ,crystalloluminescence ,chemiluminescence ,the luminescence which appears in a vacuum tube when an electric current is passed through it is sometimes spoken of as electroluminescence4 ,as electroluminescence and also thermoluminescence are really special cases of phosphorescence or fluorescence and tribo-and crystalloluminescence are closely allied1 the classification has only the merit of emphasizing the means of producing light4 ,let us examine each kind in turn in order that we may place the light of animals1 organoluminescence or bioluminescence 7or biophotogenesis71 in one of these classes4 ,all are examples of cold light1 light produced at temperature far below those observed in incandescent solids4 ,in this category should be placed also the light from salts in the bunsen flame1 for flame spectra and line spectra in general1 while only obtained at relatively high temperatures1 are not to be confused with the purely temperature radiation from the incandescent particles of carbon in a gas or candle light4 ,the sodium or lithium flame1 etc41 is not a simple function of temperature and has been spoken of as a luminescence1 pyroluminescence4 ,as the luminescence of organisms could in no manner be regarded as a pyroluminescence1 occurring at temperatures far above those compatible with life1 a consideration of this form of luminescence will be omitted4 ,some other low temperature flames are known1 such as that of ,,cs#b in air1 rich in ultra-violet rays1 despite its relatively low temperature4 ,while these are of interest to the physicist and chemist1 they can have no direct bearing on the luminescence of animals and their consideration will also be omitted4 7,see ,bancroft and ,weiser1 #aiad-aiae47 ,,thermoluminescence4--,some substances begin to emit light of shorter wave-length than red1 well below #ebe deg44 ,this is thermoluminescence4 ,diamond1 marble1 and fluorite are examples4 ,only certain varieties of fluorite show the phenomenon well4 ,a crystal of one of these varieties heated in the bunsen flame on an iron spoon will give off a white light long before any trace of redness appears in the iron4 ,other crystals may luminesce in hot water4 ,in all1 this luminescence is dependent on a previous illumination or radiation of the crystal4 ,if kept in the dark for a long time no trace of light appears when fluorite is placed at a temperature of #ajj deg41 but after a short exposure to the light of an incandescent bulb1 although no light can be observed in the fluorite at room temperature1 quite a bright glow appears at #ajj deg44 ,calcium1 barium1 strontium1 magnesium and other sulphates containing traces of manganese sulphate1 show a similar phenomenon after exposure to cathode rays 7,wiedemann and ,schmidt1 #ahie b74 ,they emit light during bombardment1 but this soon ceases when the rays are cut off4 ,if the sulphates are now heated they give off light1 red in the case of ,mg,s,o#d ,mn,s,o#d1 green in the case of ,ca,s,o#d ,mn,s,o#d4 ,the power to emit light on heating may be retained for months after the exposure to cathode rays4 ,the emission of light by bodies after previous illumination or radiation is called phosphorescence and will be considered below4 ,it would seem that the cases of thermoluminescence with which we are acquainted are really cases of phosphorescence intensified by rise of temperature4 ,the spectrum of thermoluminescent bodies1 also1 is similar to that of phosphorescent ones4 7,see ,fig4 #c47 ,however1 not all phosphorescent materials are also thermoluminescent4 ,the production of light by animals is quite another phenomenon from thermoluminescence4 ,,phosphorescence ,,and ,,fluorescence4--,although the word phosphorescence has been used in a very loose way to indicate all kinds of luminescence1 and particularly that of phosphorus or of luminous animals1 to the physicist it has a very definite meaning1 namely1 the absorption of radiant energy by substances which afterwards give this off as light4 ,phosphorescence does not strictly apply to the light of white phosphorus4 ,if the radiant energy is light 7visible or ultra-violet7 we speak of photoluminescence1 if cathode rays we have cathodoluminescence1 if anode rays1 anodoluminescence1 and if ,x-rays 7,roentgen rays7 we have radioluminescence4 ,inasmuch as the alpha1 beta1 and gamma rays of radium correspond to the anode1 cathode1 and ,x-rays1 respectively1 radium radiation also produces luminescence in many kinds of material4 ,if the material gives off the light only during the time it is radiated we speak of fluorescence2 if the light persists we speak of phosphorescence4 ,the distinction is perhaps a purely arbitrary one1 as there are a great many substances which give off light for only a fraction of a second 7#a_/ejjj sec4 in some cases7 after being illuminated 7photoluminescence74 ,some substances also1 which fluoresce at ordinary temperatures1 will phosphoresce at low temperatures4 ,phosphorescence is exhibited chiefly by solids1 fluorescence also by liquids and vapors4 ,special means must be used to observe a phosphorescence of short duration4 ,e4 ,becquerel has devised an apparatus for doing this1 a phosphoroscope4 ,it consists of revolving disks with holes in them between which the object to be examined is placed4 ,the holes are so arranged that the object is first illuminated and then completely cut off from light4 ,the observer looking at it through another hole sees it at the moment it is not illuminated and can thus tell if it is phosphorescing4 ,by determining the rate of revolution of the disks it is easy to calculate how long the phosphorescence persists4 ,while relatively few solids phosphoresce after exposure to light at ordinary temperature a large number of these acquire the property at the temperature of liquid air4 ,included in the list are such biological products as urea1 salicylic acid1 starch1 glue and egg shells4 ,the temperature also affects the wave-length and hence the color of the light given off4 ,usually the higher the temperature the shorter the wave-length1 but in the case of some bodies 7,sr,s7 the wave-lengths become longer at the higher temperature4 ,the best known cases of phosphorescence which occur at room temperature and the group to which the word phosphorescence is commonly applied1 are those of the alkaline earth sulphides 7,ba,s1 ,ca,s1 ,sr,s7 and ,zn,s4 ,an ,italian1 ,vicenzo ,cascariolo1 is said to have discovered the ,bologna stone 7,ba,s,o#d7 which1 by calcination with charcoal1 gave an impure phosphorescent ,ba,s or lapis solaris4 ,canton's phosphorus 7,ca,s7 was later prepared by heating a mixture of three parts of sifted calcined oyster shells with one part of sulphur to an intense heat for one hour4 ,hulme spoke of it as the light magnet of ,canton1 because of its power of attracting and absorbing light4 ,the pure sulphides do not show this property4 ,only if small amounts of some other metal such as ,cu1 ,pb1 ,ag1 ,zn1 ,sb1 ,ni1 ,bi1 or ,mn are present1 will the sulphide phosphoresce4 ,one part of impurity in a million is often sufficient4 ,such mixtures1 together with a flux of ,na#b,,so#d1 ,li#c7,,po#d7b or some other fusible salt constitute a phosphor4 ,a phosphor is in reality an example of a solid solution and is the basis of some kinds of luminous paints4 ,the intensity and duration of a phosphorescent light depend chiefly on the nature of the exciting rays1 the color chiefly on the impurity present but the alkaline earth metal also exerts an influence4 ,rise in temperature increases the intensity but diminishes the duration1 so that the total amount of light emitted is about constant at different temperatures4 ,the spectrum of most phosphorescent substances is made up of one or more continuous bands having maxima at different wave-lengths4 ,in the light incident on a phosphorescent substance are also bands of light rays which are absorbed and whose wave-lengths are more efficient than others in stimulating phosphorescence4 ,these bands in the phosphorescent light are usually of longer wave-length than those in the light which excites the phosphorescence4 ,this fact is known as ,stokes' ,law1 but it has been found not to be universally true4 ,curiously enough1 red and infra-red rays have the power of annulling phosphorescence after a momentary increase in brightness and phosphorescing materials have been used to determine if infra-red rays are given off in the light of the firefly4 ,ives 7#aiaj7 showed that infra-red radiation had no power of quenching the light of the firefly as it does the phosphorescent light of ,sidot blende 7,zn,s71 one fact tending to show that the firefly's light is not due to phosphorescence4 ,fig4 #c is a reproduction of a photograph of the phosphorescence spectrum of ,zn,s4 ,illustration3 ,,fig4 #c4 ,spectrum of zinc sulphide phosphorescence 7after ,ives and ,luckiesh74 ,photographs were taken by a special device one minute 7middle7 and fifteen minutes 7bottom7 after exposure to the light of the mercury arc and compared with a helium spectrum 7top74 ,in the middle photograph1 the mercury exciting lines are visible4 ,it will be noted that the narrow band of phosphorescent light does not shift its position during decay of phosphorescence4 ,other facts show that the light of luminous animals is in no sense a phosphorescence and is quite independent of previous illumination of the animal4 ,luminous bacteria will continue to luminesce although they are grown in the dark for many weeks4 ,indeed strong light has a bactericidal action on these forms similar to that with ordinary bacteria4 ,with some marine forms light has an inhibiting effect4 ,they lose their power of luminescence during the day and only regain it at dusk or when kept in the dark for some time4 ,indeed1 ordinary light never has the effect of causing luminescence in the same sense as it causes phosphorescence of ,ca,s4 ,fluorescence is most efficiently excited by the cathode rays of a vacuum tube4 ,they not only cause the residual gas in the tube to glow 7electroluminescence7 by which their path may be followed with the eye1 but also a vivid fluorescence of the glass walls of the tube1 yellow green with sodium glass1 blue green with lead and lithium glass4 ,li,cl#b in the path of cathode rays gives off a blue light2 in the path of anode rays a red light2 ,na,cl a blue cathodoluminescence and a yellow anodoluminescence4 ,the spectrum of the latter is a line spectrum of ,li or ,na1 showing the characteristic red or yellow lines similar to those observed where ,li or ,na is held in the bunsen flame4 ,the spectrum of the salts under excitation of cathode rays is a short continuous one in the blue region4 ,fluorescent spectra in general are of this nature1 made up of short bands of light in one or more regions4 ,diamonds1 rubies and many minerals fluoresce brilliantly in the path of cathode rays4 ,some specimens of fluorite 7,ca,f#b7 show the phenomenon especially well1 whence the name fluorescence4 ,fluorescent screens of barium platinocyanide1 willemite 7,zn#b,si,o#d71 ,sidot blend 7,zn,s7 or ,scheelite 7,ca tungstate7 are frequently employed to render visible ,x-rays4 ,the luminous paint most used at the present time is ,zn,s containing a trace of radium salt4 ,the rays of the radium continually emitted cause a steady fluorescence of the ,zn,s4 ,indeed1 if one examines the paint on the hands of a watch with a lens the flash of light from the impact of alpha particles on the ,zn,s can be distinctly seen1 as in the spinthariscope4 ,some animal tissues and fluids1 especially the lens of the eye1 will luminesce in the path of radium rays1 as shown by the experiments of ,exner 7#aijc71 but there is no evidence that luminous animals are especially active in this respect4 ,ultra-violet rays have the same action4 ,the luminous material of practically all luminous forms1 if dessicated sufficiently rapidly1 can be obtained in the form of a dry powder which will give off light when moistened with water4 ,coblentz 7#aiab7 has exposed this dry material to light1 to the ultra-violet spark1 and to ,x-rays and in no case has a phosphorescence or fluorescence ever been observed4 ,i have examined the action of radium upon ,cypridina light4 ,there was no intensifying or diminishing effect of twenty milligrams of radium 7probably the bromide7 on a luminous solution of ,cypridina material1 nor was phosphorescence or fluorescence excited in a non-luminous extract of the animal4 ,we must conclude that animal light is not a fluorescence of any substance due to radiation produced by the animals themselves4 ,many solutions show fluorescence in strong lights4 ,this is especially marked in quinine sulphate1 mineral oils1 eosin1 fluorescein1 esculin1 rhodamin1 chlorophyll1 etc4 ,the fluorescence of eosin in #aj-h grams per cubic centimetre is visible in daylight and #aj-ae grams per cubic centimetre in the beam from an arc lamp4 ,it is difficult to realize that the bluish fluorescence of quinine sulphate is really an emission rather than a reflection of light4 ,but a test tube of quinine sulphate solution held in the ultra-violet region of a spectrum will glow with a pale blue light1 although it is not illuminated with any rays that are visible to our eyes4 ,concerning this1 ,stokes1 to whom the word fluorescence and much of our knowledge of the subject is due1 says1 ,it was certainly a curious sight to see the tube 7containing quinine sulphate solution7 instantaneously lighted up when plunged into the invisible rays2 it was literally 'darkness visible4' ,quinine sulphate absorbs the ultra-violet converting these rays into visible blue ones4 ,its spectrum is a short continuous one4 ,most fluorescent substances convert short into longer wave-lengths 7,stokes' ,law71 but some may cause the reverse change4 ,a substance1 fluorescent in solution1 has been found in a few luminous animals1 notably in several species of fireflies and also in a non-luminous beetle4 ,it is called pyrophorine or luciferesceine4 ,dubois 7#ahhf7 has ascribed to pyrophorine the power of absorbing invisible rays and transforming them into visible ones1 thus increasing the animal's light4 ,that this is not the case has been shown by the work of ,coblentz 7#aiji74 ,he photographed the spectrum of the firefly's light and the fluorescent spectrum of luciferesceine4 ,the latter is almost complementary to the former 7see ,fig4 #d7 and no trace of the fluorescent spectrum appears in the spectrum of the light of the firefly4 ,mc,dermott 7#aiaa a7 has studied the properties of luciferesceine and regards it merely as an incidental material found in many animals of the ,lampyridae 7in some non-luminous forms7 and having no connection with the light production4 ,a trace of alkali usually increases and acid inhibits the fluorescence of solutions4 ,illustration3 ,,fig4 #d4--,spectrum of fluorescent substance found in fireflies below 7#b7 and of firefly luminescence above 7#b7 compared with helium vacuum tube 7#a7 7after ,coblentz74 ,,triboluminescence ,,and ,,piezoluminescence4--,under this head are grouped a number of light phenomena which at first sight may appear to be electrical in nature but in reality are not4 ,the light is produced by shaking1 rubbing1 or crushing crystals1 and only crystalline bodies appear to show triboluminescence or piezoluminescence4 ,a striking case is that of uranium nitrate4 ,gentle agitation of the crystals is sufficient to give off sparks of light which much resemble the scintillations of dinoflagellates when sea-water containing these animals is agitated4 ,if ,romberg's phosphorus1 which is fused ,ca,cl#b1 is rubbed on the sleeve1 it glows with a greenish light4 ,lumps of cane sugar rubbed together will glow4 ,saccharin crystals will also light if shaken and ,pope 7#ahii7 found that the bluish light of saccharin was bright enough to be visible in a room in daytime4 ,it only appeared from impure crystals and freshly crystallized specimens4 ,other crystals1 also1 have been found to lose their power of lighting after a time4 ,among biological substances1 cane sugar1 milk sugar1 mannite1 hippuric acid1 asparagin1 r-tartaric acid1 l-malic acid1 vanillin1 cocaine1 atropin1 benzoic acid1 and many others show triboluminescence4 ,a long list is given by ,tschugaeff 7#aija71 by ,trautz 7#aije71 and by ,gernez 7#aije74 ,the spectrum is a short continuous one1 the waves emitted depending on the kind of crystal4 ,thus the color of the light varies among different santonin derivatives from yellow to green4 ,in saccharin it is blue4 ,although the light produced by some living organisms resembles triboluminescence in that it may be evoked by rubbing or shaking the animals1 it is in reality fundamentally different since it is dependent on the presence of oxygen whereas triboluminescence is not4 ,,crystalloluminescence4--,crystallolumi nescence is observed when solutions crystallize4 ,it was described by ,bandrowski 7#ahid1 #ahie7 in arsenious oxide1 in ,na,f1 or if ,h,cl or alcohol is added to hot saturated ,na,cl solution4 ,a bluish light with sparkling points appeared4 ,all well authenticated cases are exhibited by simple inorganic salts and these are also all triboluminescent4 ,the reverse is not true1 however2 many triboluminescent substances are not crystalloluminescent4 ,crystalloluminescence is much less widespread than triboluminescence4 ,trautz 7#aije7 has studied the matter in a number of compounds and comes to the conclusion that the light is really a special case of triboluminescence in which the growth of individual crystals causes them to rub together4 ,the light becomes much brighter on stirring a mass of crystals which exhibit crystalloluminescence4 ,while in some cases crystalloluminescence is unquestionably due to the triboluminescence of crystals rubbing against each other it is not in every case1 as has been clearly shown by the work of ,weiser 7#aiah b74 ,he studied luminescence of saturated aqueous alkali halide solutions 7,na,cl1 ,k,cl1 etc417 upon addition of alcohol or of ,h,cl4 ,the salt crystallizes out under these conditions and ,weiser found that the light is brightest when the conditions of concentration of alcohol or of ,h,cl are such as to cause heaping up of ,na and ,cl ions4 ,he believes that the bluish light which appears is due to the combination of ions in the reaction1 ,na ,cl- ,na,cl4 ,only if this proceeds rapidly enough does luminescence occur4 ,weiser studied also the crystalloluminescence and triboluminescence of ,as,cl#c and of ,k#b,,so#d4 ,by photographing the luminescence through color screens of different absorptive power 7,weiser1 #aiah1 a7 a spectrum of the light could be obtained1 and it was found to be identical in both the tribo- and crystalloluminescent light2 in the case of ,as,cl#c1 a band in the green-blue1 blue and violet4 ,weiser believes the light in this case also to come from recombination of the ions1 ,as #c;,cl- ,as,cl#c1 and that crystalloluminescence in general is due to rapid reformation of molecules from ions broken up by electrolytic dissociation while triboluminescence is due to rapid reformation of molecules from ions broken up by violent disruption of the crystal4 ,of course in triboluminescent organic crystals which do not dissociate into ions1 some other reaction must be responsible for the light4 ,one thing seems certain1 that the two types of luminescence are similar4 ,as ,bigelow#a remarks1 ,it is altogether probable that the cause of this 7crystalloluminescence7 whatever it may be1 is the same as the cause of triboluminescence1 whatever that may be4 #a ,theoretical and ,physical ,chemistry1 #aiab1 p4 #eaf4 ,crystals are not found in the luminous organs of animals with the exception of the fireflies4 ,in these a layer of cells occurs 7see ,chapter ,,iv7 filled with minute crystals of one of the purine bodies 7xanthin or uric acid74 ,one might surmise that the light of the animal was a crystalloluminescence accompanying the formation of these crystals4 ,it is easy to show1 however1 that the light comes not from the crystal layer but from another layer of cells containing large granules4 ,it is also dependent on the presence of oxygen while crystalloluminescence takes place in the absence of oxygen4 ,the crystal layer possibly serves as a reflector4 ,its significance will be discussed in a later chapter4 ,illustration3 ,,fig4 #e4--;,dubois's figures showing transformation of photogenic granules to crystals 7after ,dubois74 ,the light of luminous organisms is quite generally associated with granules4 ,in one of the centipedes 7,orya barbarica71 which produces a luminous secretion1 ,dubois 7#ahic7 has described the transformation of these granules into crystals and at one time he supposed the light to be a crystalloluminescence4 ,he later reversed this opinion and1 certainly1 examination of his drawings which are reproduced in ,fig4 #e does not convince one of the actuality of crystal formation4 ,the phenomenon of lyoluminescence1 described by ,wiedemann and ,schmidt 7#ahie7 as a light accompanying the solution of colored 7from exposure to cathode rays7 crystals of ,li1 ,na1 or ,k chlorides1 is probably due to a triboluminescence from stirring of the crystals during solution4 ,,chemiluminescence4--,as the name implies1 chemiluminescence is the production of light during a chemical reaction at low temperatures4 ,this does not mean that the other types of luminescence are not connected with chemical reactions--using the word reaction in a broad sense--for we have reason to believe that in some cases spectra are not characteristic of the element as such but are rather characteristic of a particular reaction in which the element takes part 7dissociation into ions1 changes from monovalent to bivalent condition1 etc47 and that this is the reason one element may show various spectra under different conditions 7,bancroft1 #aiac74 ,the chemiluminescences are rather oxidation reactions involving the absorption of gaseous or dissolved oxygen and may be very easily distinguished from all the previously mentioned luminescences by this criterion4 ,they should1 perhaps1 more properly be called oxyluminescences4 ,the glow of phosphorus is the best known case1 recognized since phosphorus was first prepared by ,brandt in #affi4 ,it is interesting to note that when first prepared phosphorus was regarded as a peculiarly persistent type of phosphor1 i4e41 a material akin to the impure alkaline earth sulphides4 ,fresh cut surfaces of ,na and ,k metal will glow in the dark for some time1 especially if warmed to #fj deg4-#gj deg4 7,linnemann1 #aheh74 ,a film of oxide is formed over the surface1 showing definitely that oxidation has occurred4 ,ozone oxidizes organic matter with an accompanying glow 7,fahrig1 #ahij2 ,otto1 #ahif74 ,the light from ozone acting on pyrogallol solution is especially bright under certain conditions4 ,radziszewski 7#ahgg1 #ahhj7 gives a long list of substances1 chiefly essential oils1 which luminesce if slowly oxidized in alcoholic solutions of alkalis4 ,formaldehyde1 dioxymethylen1 paraldehyde1 metaldehyde1 acrolein1 disacryl1 aldehydeammonia1 acrylammonia1 hydrobenzamid1 lophin1 hydroanisamid1 anisidin1 hydrocuminamid1 hydrocinamid1 besides waxes1 and such biological substances as glucose1 lecithin1 cholesterin1 cholic1 taurocholic1 and glycocholic acids1 and cerebrin1 all luminesce on oxidation4 ,radziszewski himself and many other authors have compared the light of organisms to this type of luminescence4 ,indeed the incorrect identification of granules found in the cells of practically all luminous tissues as oil droplets1 is largely due to the influence of ,radziszewski's work4 ,dubois 7#aija b7 has added esculin1 and ,trautz 7#aijd-e7 many aldehydes and phenol derivatives1 including vanillin1 papaverin1 tannic and gallic acids1 besides glycerol and mannite to the list of biological substances oxidizing with light production4 ,guinchant 7#aije7 has described oxyluminescence of uric acid and asparagine1 ,weitlaner 7#aiaa7 of substances in humus and ,mc,dermott 7#aiac7 of substances in urine and the anaerobic alkaline hydrolysis products of glue and ,witte's peptone4 ,pyrogallol is especially prone to luminesce1 as was first noticed by ,lenard and ,wolf 7#ahhh7 in developing a photographic plate with pyrogallol developer4 ,later the luminescence was studied in some detail by ,trautz and ,schloringin 7#aijd-e7 who developed the well-known luminescent mixture of pyrogallol1 formaldehyde1 ,k#b;,,co#c and ,h#b,o#b4 ,as ,i have shown1 pyrogallol can be oxidized in a great many different ways1 and some of these are of great interest1 for they very closely imitate the mechanism for the production of light in organisms4 ,these are recorded in ,table #c1 which also includes various other types of oxyluminescence of general or biological interest4 ,,table #c ,types of ,oxyluminescent ,reactions #a4 ,oxidation in air spontaneously4 7a7 ,at ordinary temperatures4 ,phosphorus4 ,fresh-cut surfaces of ,na or ,k4 ,thiophosgene and ,thio-ethers 7,,rcs4,,or74 7b7 ,at melting or vaporizing points4 7,fats1 terpenes1 sugars1 resins1 gums1 ether1 silk and others47 #b4 ,oxidation in aqueous or alcoholic alkalies4 7,many organic substances47 #c4 ,oxidation in hypoiodites1 hypobromites1 or hypochlorites4 7,many organic substances47 #d4 ,oxidation in peroxides 7,h#b,o#b or ,na#b,o#b74 7,many organic substances47 #e4 ,oxidation in ozone4 7,many organic substances47 #f4 ,oxidation in acid permanganate4 7,pyrogallol47 #g4 ,oxidation in persulfates and perborates4 7,formaldehyde1 paraformaldehyde47 #h4 ,oxidation in perchlorates1 periodates1 and perbromates4 7,palmitic acid47 #i4 ,combination of #b and #d4 7,many organic substances47 #aj4 ,combination of #c and #d4 7,many organic substances47 #aa4 ,oxidation with ,h#b,o#b and haemoglobin or vegetable oxidases4 7,pyrogallol1 gallic acid1 lophin1 esculin47 #ab4 ,oxidation with ,h#b,o#b and ,mn,o#b1 ,fe#b;,fe7,,cn7#f ,mn7,,oh7#b ,mn7,,oh7#c ,ag#b,o1 chromium oxide1 cobalt oxide4 7,pyrogallol47 #ac4 ,oxidation with ,h#b,o#b and ferrocyanides1 chromates1 bichromates1 permanganates1 ,fe salts1 and ,cr salts4 7,pyrogallol1 esculin47 #ad4 ,oxidation with ,h#b,o#b and collodial ,ag4 ,pt4 ,pd4 ,au4 7,pyrogallol47 ,the spectrum of chemiluminescent reactions has been described in a few instances as continuous but no definite measurements of its extent have been made4 ,radziszewski 7#ahhj7 found the light of lophin oxidized in alcoholic caustic alkali1 examined with a two-prism spectroscope1 to give a continuous spectrum1 brightest at ,e1 with the red and violet ends lacking4 ,trautz 7#aije1 p4 #aja7 states that the pyrogallol-formaldehyde-,na#b;,,co#c-;,h #b,o#b reaction gives a continuous spectrum from the red to the blue green with maximum brightness in the orange4 ,weiser 7#aiah a7 has studied the spectra of some chemiluminescent reactions by photographing the light behind a series of color screens4 ,he finds also that the spectra are short1 with maximum intensity in various regions4 ,thus1 amarin oxidized by chlorine or bromine1 extends from the yellow to greenish blue with a maximum in the green while phosphorus1 dissolved in glacial acetic acid and oxidized with ,h#b,o#b1 luminesces from yellow green to violet4 ,the spectra of luminous animals are quite similar to those of chemiluminescent reactions4 ,moreover1 as we have seen1 chemiluminescence is essentially an oxyluminescence1 since oxygen is necessary for the reaction4 ,all luminous animals also require oxygen for light production4 ,therefore1 bioluminescence and chemiluminescence are similar phenomena and they differ from all the other forms of luminescence which we have considered4 ,the light from luminous animals is due to the oxidation of some substance produced in their cells1 and when we can write the structural formula of this photogenic substance and tell how the oxidation proceeds1 the problem of light production in animals will be solved4 ,,chapter ,,iii ,,physical ,,nature ,,of ,,animal ,,light ,interest in the light of animals from a physical standpoint has centred around questions of quality1 efficiency and intensity1 but in only one group of luminous animals1 the beetles1 have accurate measurements of these characteristics been made4 ,this is due in part to the abundance of these forms and their appeal to human interest and in part because they are among the brightest of luminous organisms4 ,weak lights are not only difficult to measure but1 when dispersed to form spectra1 give bands so faint that their limits are very difficult to see and more so to photograph4 ,very few organisms produce light visible to the fully light-adapted eye4 ,although their light may seem quite bright to the dark-adapted eye1 the dark-adapted eye is a poor judge of the quality1 i4e41 the color of a light4 ,this is because of the ,purkinje phenomenon1 a change in the region of maximum sensibility of the retina with change in intensity of the light4 ,for an equal energy spectrum1 to the normal1 completely light-adapted eye1 yellow-green light of wave-length1 lambda 4#efe mu1 appears the brightest1 but when the light is made fainter the maximum shifts first to the green and then to the blue4 ,the dark-adapted eye can see green or blue better than yellow and for this reason weak lights will appear more green or blue than stronger ones of the same energy distribution4 ,also two weak lights of the same spectral composition may appear different in color if they differ much in intensity4 ,this is illustrated in ,fig4 #f4 ,illustration3 ,,fig4 #f4--,visibility curves for three illuminations showing the shift in region of maximum visibility1 or ,purkinje phenomenon 7after ,nutting74 ,the shift in sensibility of the eye occurs in illuminations of between #j4e and #ej metre-candles and represents a change from central cone vision 7high intensities7 to peripheral rod vision 7low intensities74 ,the fovea centralis lacks rods and this part of the eye becomes practically color blind at very low intensities of light4 ,below #j4e and above #ej metre-candles visibility varies but little with change in intensity4 ,it is clearly necessary then to distinguish between the physical objective phenomenon of light and the physiological subjective sensation of light4 ,it is a fact that different luminous animals produce light of quite different colors as judged by our eye4 ,a range of spectral tints has been described which extends from red to violet but yellowish1 greenish and bluish tints are commonest4 ,indeed one or two animals possess several luminous organs emitting lights of different colors4 ,this is true in a ,south ,american firefly1 ,phengodes1 whose lights are red and greenish yellow1 and in the deep sea squid1 ,thaumatolampas diadema1 which produces lights of three colors1 two shades of blue and red4 ,the red light in the case of the squid appears to be due to a red color screen formed by the chromatophores1 but in ,phengodes no screen is present4 ,,table #d ,wave-lengths of ,fraunhofer ,lines and ,prominent ,lines in ,line ,spectra ,,fraunhofer ,,lines ,line ,color ,wave-lengths ,source 7 mu mu mu_/#ajjj7 ---------------------------------------- ----------------------------- ,a ,red #gei4d 7band7 ,oxygen in atmosphere4 a ,red #gah4e 7band7 ,water vapor atmosphere4 ,b ,red #fhf4g ,oxygen vapor atmosphere4 ,c ,red #fef4c ,hydrogen in sun4 ,d#a ,d#b ,yellow #ehi4f1 #ehi4j ,sodium in sun4 ,e ,green #ebg4j ,calcium in sun4 b#a b#b b#d ,green #eah4d1 #eag4c1 #eaf4h ,magnesium in sun4 ,f ,blue #dhf4a ,hydrogen in sun4 ,g ,violet #dcj4h ,calcium in sun4 ,h ,k ,violet #cif4i1 #cic4d ,calcium in sun4 ---------------------------------------- ----------------------------- ,,bunsen ,,flame ,,lines ,source ,color ,wave-lengths 7 mu mu mu_/#ajjj7 ---------------------------------------- ----- ,potassium ,red #gfi4i1 #gff4e 7double7 ,lithium ,red #fgj4h ,sodium ,yellow #ehi4f1 #ehi4j 7double7 ,thallium ,green #ece4a ,magnesium ,green #eah4d ,strontium ,blue #dfj4g ---------------------------------------- ----- ,p,l,ue,c,k,e,r ,,tube ,,lines ,source ,color ,wave-lengths 7 mu mu mu_/#ajjj7 ---------------------------------------- ----- ,mercury ,yellow #egi4j1 #egf4i ,green #edf4a ,blue #dia4f1 #dce4h ,violet #djg4h1 #djd4g ,hydrogen ,red #fef4c ,blue #dhf4a1 #dcd4a ,helium ,red #gbh4b1 #gjf4e1 #ffg4h ,yellow #ehg4f ,green #ejd4h1 #eja4f1 #dib4b ,blue #dga4c1 #ddg4b ,violet #dch4h1 #djb4f1 #chh4h ---------------------------------------- ----- ,as we have seen1 difference in color of the light does not necessarily indicate difference in spectral composition because of the ,purkinje effect4 ,however1 examination of the spectrum of various luminous forms has very clearly indicated that the different colors are really due to light rays of different wave-length and are not the result of any subjective phenomena4 ,to facilitate comparison1 spectral lines and colors are given in ,table #d4 ,the first adequate observations on the spectra of luminous animals were made by ,pasteur 7#ahfd71 who studied ,pyrophorus and found a continuous spectrum unbroken by light or dark bands4 ,lankester 7#ahfh7 discovered a similar continuous spectrum in ,chaetopterus insignis and placed its limits from line #e to #aj on ,sorby's ,scale 7about lambda #j4ee mu to lambda #j4dd mu74 ,young 7#ahgj7 first recorded the limits of the firefly spectrum as a little above ,c 7lambda 4#fefc mu7 to ,f 7lambda 4#dhfa mu74 ,since then a number of luminous forms have been examined and all are found to give short continuous spectra 7not crossed by light or dark bands or lines7 lying in different color regions4 ,thus1 ,conroy 7#ahhb7 examined the glowworm 7,lampyris noctiluca7 light and observed a band extending from lambda #j4eah mu to lambda #j4fef mu4 ,dubois 7#ahhf7 states that the spectrum of ,pyrophorus noctilucus1 the ,west ,indian ,cucullo1 extends from slightly further than the ,fraunhofer ,b line to the ,f line1 while ,langley and ,very 7#ahij71 working on the same form1 placed the limits at lambda #j4dfh mu to lambda #j4fdj mu4 ,it consists1 then1 of a broad band chiefly in the green and yellow4 ,but1 would the light not extend farther were it bright enough to be seen8444 if the light of the insect were as bright as that of the sun would it not extend equally far on either side of the spectrum8 ,it is impossible to increase the intrinsic brilliancy by any optical device1 but if it be impossible to make the light of the insect as bright as that of the sun1 it is on the other hand quite possible to make the light of the sun no brighter than that of the insect 444 ,langley and ,very investigated this question1 forming a solar spectrum from sunlight of the same intensity as that of ,pyrophorus and a ,pyrophorus spectrum together in the same field of the spectroscope4 ,the latter was very much shorter than the solar spectrum1 showing that its length was not due to weakness of the red and blue rays but to their absence4 ,later ,ives and ,coblentz 7#aiaj7 photographed the spectrum of a firefly 7,photinus pyralis71 together with that of a carbon glow lamp1 on plates sensitive to all wave-lengths of visible rays under conditions which would have recorded all visible radiations given off4 ,they found the spectrum to extend only from lambda #j4ea mu to lambda #j4fg mu 7,fig4 #g74 ,another species of firefly 7,photuris pennsylvanica7 was found by ,coblentz 7#aiab7 to give a spectrum extending from lambda #j4ea mu to lambda #j4ei mu 7,fig4 #h74 ,the ,photinus light extends much further into the red and it is easy to distinguish between ,photinus and ,photuris in nature1 merely by the reddish tint of the light of the former4 ,these photographic records show conclusively that the color of the light of luminous animals is not a subjective phenomenon due to the ,purkinje effect and the low intensity of the light1 but is real1 an actual difference in spectral composition of the light emitted4 ,neither is it due1 at least in the fireflies examined1 to the existence of color screens which absorb certain rays1 allowing only those of a definite color to pass4 ,the spectra of forms thus far investigated are reproduced in ,fig4 #i and recorded in ,table #e4 ,it will be noted that they vary considerably in position but are all of the same type4 ,the spectrum of ,cypridina hilgendorfii is the longest thus far investigated 7lambda 4#faj mu to lambda 4#dae mu71 extending well into the blue1 and the light of this form is very blue in appearance4 ,illustration3 ,,fig4 #g4--,spectra of carbon glow lamp1 ,a1 firefly 7,photinus pyralis72 ,b1 and helium vacuum tube1 ,c 7after ,ives and ,coblentz74 ,illustration3 ,,fig4 #h4--,spectra of helium vacuum tube 7#a72 carbon glow lamp 7#b72 the firefly1 ,photinus pyralis 7#c72 and the firefly ,photuris pennsylvanica 7#d7 7after ,coblentz74 ,illustration3 ,,fig4 #i4--,spectra of various luminous animals 7after ,mc,dermott74 #a4 ,portion of the visible solar 7grating7 spectrum showing ,fraunhofer lines4 #b4 ,pyrophorus noctilucus 7,langley and ,very47 #c4 ,lampyris noctiluca 7,conroy74 #d4 ,photinus pyralis 7,ives and ,coblentz74 #e4 ,photinus consanguineus 7,coblentz74 #f4 ,photuris pennsylvanica 7,coblentz74 #g4 ,phengodes laticollis 7,mc,dermott74 #h4 ,bacterium phosphoreum1 ,b4 phosphorescens or ,bacillus photogenus 7,molish74 #i4 ,photobacterium indicum 7,barnard74 #aj4 ,mycelium ,x 7,molish74 #aa4 ,luminous bacteria 7,foerster74 #ab4 ,agaricus sp48 7,ludwig74 #ac4 ,fluorescent spectrum of luciferesceine of ,photinus pyralis 7,coblentz74 ,only the extreme ends of the bands are shown and no attempt is made to indicate the relative density of different portions of the spectra4 ,,table #e4--,limits of ,spectra of ,various ,luminous ,organisms ,light ,spectrum 7 mu7 ,emission ,observer ,method and remarks maximum ---------------------------------------- -------------------------------- ,cypridina #j4faj-j4dae ,harvey1 ,eye observation1 hilgendorfii #aiai ,zeiss comparison spectroscope4 ,chaetopterus #j4ee-j4dd ,lancaster1 ,eye observation4 insignis 7approximately7 #ahfh ,pyrophorus #j4gb-j4dhf ,dubois1 ,eye observation4 noctilucus #ahhf ,pyrophorus 4#fdj - 4#dfh #j4eg ,langley ,eye observation noctilucus and ,very1 and comparison 7thoracic #ahij with solar light7 spectrum of equal intensity4 ,pyrophorus 4#ffc - 4#dfc noctilucus 7abdominal light7 ,photinus 4#fg - 4#ea ,ives and ,photographic pyralis ,coblentz1 comparison with #aiji carbon glow lamp of equal intensity4 ,photuris 4#ei - 4#ea 4#eeb ,coblentz1 ,photographic pennsylvanica #aiab comparison with carbon glow lamp of equal intensity4 ,photinus 4#fe - 4#eb 4#egh ,coblentz1 ,photographic consanguineus #aiab comparison with carbon glow lamp of equal intensity4 ,phengodes 4#fe - 4#eb ,mc,dermott1 ,eye observation4 laticollis #aiaa e ,lampyris 4#fef- 4#eah ,conroy1 ,eye observation4 7glow worm7 #aiaj ,photinus 4#fgj- 4#dhg ,young1 ,eye observation #ahgj direct vision spectroscope4 ,bacteria ,g to ,f extending ,barnard1 ,photographic4 toward ,d for #aijb long exposure ,bacteria ,somewhat beyond ,fisher1 ,eye observation4 ,g to ,d #ahhh ,bacteria 4#eh - 4#dc ,foerster1 ,eye observation #ahhg ,zeiss4 ,abbe microspectral ocular4 ,bacteria 4#ejj to 4#cej ,bright ,forsyth1 ,photographic1 band #aiaj quartz at 4#d spectroscope4 ,agarious #j4ef-j4dh ,ludwig1 ,eye observation1 melleus 7approximately7 #ahhd ,sorby ,brown microspectroscope4 ,xylaria 4#ed - 4#df ,ludwig1 ,eye observation1 hypoxylon 7approximately7 #ahhd ,sorby ,brown microspectroscope4 ,micrococcus b into the ,ludwig1 ,eye observation1 ,pflugeri violet #ahhd ,sorby ,brown microspectroscope4 ,mycelium ,x 4#egj - 4#dhj ,molish1 ,eye observation1 #aijd1 ,zeiss comparison book spectroscope4 ,bacterium 4#egj - 4#dej ,molish1 ,eye observation1 phosphoreum #aijd1 ,zeiss comparison book spectroscope4 ,bacterium 4#egj - 4#dej ,molish1 ,eye observation1 phosphorescens #aijd1 ,zeiss comparison book spectroscope4 ,bacillus 4#egj - 4#dej ,molish1 ,eye observation1 photogenes #aijd1 ,zeiss comparison book spectroscope4 ,pseudomonas 4#egj - 4#dej ,molish1 ,eye observation1 lucifera #aijd1 ,zeiss comparison book spectroscope4 ---------------------------------------- -------------------------------- ,as first shown by ,dubois 7#ahhf7 for ,pyrophorus1 and confirmed by myself for ,cypridina1 the light is not polarized in any way4 ,i may add that the ,cypridina light like any other light may be polarized by passing through a ,nicol prism4 ,several writers ,dubois 7#aiad book71 ,fischer 7#ahhh71 ,molisch 7#aijd book7 have noticed that the light of luminous bacteria changes in color if grown on different culture media4 ,light which is silver white on dead fish becomes greenish on salt-peptone-gelatin media and more yellow on salt-poor media4 ,peron 7#ahjd7 and ,panceri 7#ahgb7 describe the light of ,pyrosoma as yellow to greenish after death of the animal and reddish on stimulation2 then fading out through orange1 yellow1 greenish and azure blue4 ,polimanti 7#aiaa7 describes the normal light of ,pyrosoma as greenish1 and states that as the animals die1 or if they are kept at temperatures above the optimum1 the light becomes more red4 ,mc,dermott 7#aiaa1 b7 noticed that the light of fireflies placed in liquid air became decidedly reddish just before going out and on rewarming the first light to appear was reddish followed by the proper shade at higher temperatures4 ,i have frequently observed a more reddish color from luminous tissues of the firefly upon the addition of coagulants such as alcohol1 and have noted that the light of ,cypridina becomes weaker and more yellow at both low 7#j deg47 and high 7#ej deg47 temperatures4 ,the meaning of these color changes will be discussed in ,chapter ,,vii4 ,the efficiency of any light may be defined in several different ways3 7#a7 ,by the percentage of visible wave-lengths in the total amount of radiation emitted1 i4e41 visible radiation divided by total 7heat1 visible1 actinic7 radiation2 7#b7 by considering1 in addition to visible radiation _/ total radiation1 the sensibility of the eye to different wave-lengths1 visible radiation x visual sensibility _/ total radiation4 ,visible radiation x visual sensibility is spoken of as luminosity2 7#c7 by the amount of light 7expressed in candles7 produced in relation to a given expenditure of energy or in relation to the cost of the energy expended4 ,thus1 of the radiation emitted from an incandescent electric lamp only a small per cent4 is light1 the rest being heat and actinic rays4 ,it is therefore very far from being #ajj per cent4 efficient4 ,if there were no infra-red or ultra-violet in the radiation from an incandescent lamp its efficiency would be #ajj per cent4 if we disregarded visual sensibility4 ,but if we take into account the fact that the eye is most sensitive to yellow green1 a source of light1 even though emitting only visible radiation1 would not be #ajj per cent4 efficient unless its maximum of emission corresponded also with the maximum of visual sensibility4 ,we shall return to this question in a later paragraph4 ,looking at the question from the standpoint of energy consumption1 the carbon incandescent lamp gives one mean spherical candle for #d4hc watts 7watt #ajg ergs per sec471 while the tungsten lamp gives one mean spherical candle for #a4f watts1 about one-third the energy1 and the latter is consequently more efficient4 ,as we know practically nothing of the energy transformations occurring during the process of light production in organisms1 all statements regarding the efficiency of their light are based on relations between the visible radiation and total radiation4 ,this involves a measurement of rays in the infra-red region 7heat rays7 and ultra-violet region 7actinic rays7 as well as the light rays proper1 and any other radiant energy produced4 ,while all spectroscopic investigations show that the spectrum of luminous animals never extends to the limits of the visible spectrum in either the red or violet1 it is possible that bands occur in the infra-red or ultra-violet1 and special methods must be employed to detect these4 ,radiations of all kinds1 if converted into heat on striking the blackened surface of a thermopile1 bolometer1 or radiometer can be measured by changes in temperature and the relative amounts of energy represented be compared in a common unit1 the calorie4 ,by proper screening1 all rays except the visible light rays can be cut off from the measuring instrument and the amounts of energy represented in light and in total radiation thus be determined4 ,dubois 7#ahhf7 first studied this problem in ,pyrophorus by the use of a thermopile and galvanometer and found a small amount of radiation from the luminous region in excess of that from a non-luminous region4 ,it amounted to a galvanometer deflection of #j4ie deg4 and was increased #j4c deg4 during the flash of the insect on electrical stimulation4 ,this increase of #j4c deg4 is possibly due to heat produced on muscular contraction4 ,in any case the amount of heat radiated in comparison with that of the candle is very small indeed4 ,a more careful study has been made by ,langley and ,very 7#ahij7 with the bolometer4 ,they point out first of all that the total radiation from the most powerful luminous organ 7the abdominal one7 of ,pyrophorus which affected their bolometer slightly1 would1 in the same time 7#aj seconds71 be sufficient to raise the temperature of an ordinary mercurial thermometer having a bulb #a cm4 in diameter by rather less than #b4c x #aj-f deg4 ,c4 ,we may thus gain some idea of the magnitude of the measurements to be made4 ,the radiation from ,pyrophorus which affected their bolometer was shown to be due merely to the body heat#b of the insect1 and it is largely cut off by a plate of glass which is opaque to all wave-lengths of #c mu or more4 ,these waves are given off by bodies at temperatures below #ej deg4 ,c4 and belong to quite another spectral region to that in which the invisible heat associated with light mainly appears4 ,langley and ,very then compared the radiation from a non-luminous bunsen flame and the ,pyrophorus light1 interposing a plate of glass in each case to cut off the waves longer than #c mu1 and found several hundred times more radiation in the case of the bunsen burner but1 nevertheless1 perceptible radiation from ,pyrophorus4 ,the former consisted of radiant heat shorter than lambda #c mu and extending up to the visible light rays 7lambda #j4g mu since the bunsen flame emitted no light74 ,the very slight effect of the ,pyrophorus radiation must be due to wave-lengths between lambda #c mu and lambda #j4dfh mu1 the limit of the ,pyrophorus spectrum in the blue4 ,langley and ,very assumed it to be due entirely to the band of visible light1 lambda #j4fdj mu to lambda #j4dfh mu1 and assumed that no invisible heat rays were produced4 ,all of the energy of ,pyrophorus light would therefore lie in the visible region and its efficiency 7light rays _/ heat light actinic rays7 would be #ajj per cent4 ,later1 ,langley 7#aijb7 reinvestigated the radiation of ,pyrophorus and could detect no heating whatever with the bolometer4 ,a portion of the flame of a standard sperm candle1 equal in area to the bright part of the insects1 gave under the same circumstances1 a bolometric effect of such magnitude that had the heat of the insect been #a_/hj1jjj as great as that from the candle1 it would certainly have been recognized4 ,coblentz 7#aiab7 also1 using a vacuum thermopile of ,pt and ,bi1 was unable to detect any infra-red radiation from ,photinus pyralis1 but found that the temperature of this firefly is slightly lower than the air4 ,these temperature measurements will be discussed in a later chapter4 #b ,langley and ,very evidently supposed that the body temperature of the firefly1 like the mammal or bird1 is higher than its surroundings4 ,the assumption of ,langley and ,very that the small amount of ,pyrophorus radiation passing glass is all light has been called into question by ,ives 7#aiaj71 who points out that ,langley and ,very failed to use a screen which would cut off either the visible rays or the invisible rays between #c mu and #j4g mu4 ,they really left the question open as to whether the effect of ,pyrophorus light on their bolometer was due to the visible band of rays or to this plus another band in the infra-red4 ,the firefly's actual efficiency as a light source is dependent to a large degree on the radiation being confined to the visible region4 ,if there should be found infra-red of quantity comparable to the visible1 the firefly1 while still a very efficient source would not be1 as usually supposed1 the example of an ideally efficient light produced by nature4 ,ives investigated the question further by the phosphor-photographic method4 ,in brief it consists of this3 ,phosphorescence1 which is excited in various substances by exposure to short waves 7blue1 violet or ultra-violet71 is destroyed by exposure to longer waves 7orange1 red1 infra-red74 ,thus1 a surface of ,balmain's paint or of ,sidot blende1 excited to phosphorescence and then exposed in a spectrograph1 will have areas of reduced brightness wherever long-wave energy has fallen upon it4 ,if this surface is then laid on a photographic plate for a short period1 a permanent record is obtained on the plate after development4 ,preliminary tests showed that the method was applicable in the case of weak light such as the firefly spectrum and also if the light is intermittent like the firefly4 ,with ,sidot blend 7,zn,s7 the extinguishing action extends from lambda #j4f mu to lambda #a4e mu4 ,a sheet of deep ruby glass1 which cut off all the visible rays of the firefly but allowed infra-red to pass1 was placed between the firefly light and a surface of phosphorescent ,sidot blend which was exposed to the firefly flashes for three and a half hours4 ,no extinction of phosphorescence occurred1 while without the ruby glass1 extinction1 due to the orange rays of the visible firefly light was noticeable in #bj minutes4 ,there is thus no infra-red of an intensity at all comparable to the visible as far as lambda #a4e mu1 the lower limit of the phosphor-photographic method4 ,coblentz 7#aiab7 had examined the transparency of the dry chitinous integument of various fireflies 7,fig4 #aj7 in the infra-red and reports it to be fairly transparent down to lambda #b4h mu1 opaque between lambda #b4h mu and lambda #c4h mu1 transparent again to lambda #f mu1 and opaque beyond that4 ,the infra-red could1 then1 if it were emitted1 largely pass through the integument which is similar in absorption properties to complex carbohydrates4 ,transparency of the integument to the ultra-violet was not studied4 ,illustration3 ,,fig4 #aj4--,transmissivity of the integument of fireflies to infra-red radiation 7after ,coblentz47 ,although photographs of the spectrum of firefly 7,photinus7 light show that it extends only to the beginning of the blue1 ,forsyth 7#aiaj7 reports ultra-violet radiation in luminous bacteria4 ,he exposed a plate for #dh hours to the spectrum of bacterial light dispersed by a quartz prism and got a continuous band from lambda #j4ej mu 7the lower limit of sensitivity of the plate7 to lambda #j4ce mu4 ,however1 ,mc,dermott 7#aiaa d7 was unable to observe fluorescence of p-amino-ortho-sulpho-benzoic acid1 which responds to the ultra-violet light4 ,molisch 7#aijd1 book7 photographed bacterial and fungus light through glass and through a piece of quartz and found no difference in density on the plate4 ,as the exposure was brief1 to avoid saturation1 and as the ultra-violet1 which passes quartz but not glass1 has a much greater action on the plate than visible light1 we must conclude that ultra-violet is absent4 ,ives 7#aiaj7 investigated the spectrum of ,photinus pyralis1 using a quartz spectroscope1 and found no evidence of ultra-violet radiation1 at least as far as lambda #j4baf mu4 ,it will thus be seen that the radiation from the firefly has been very carefully studied and that no waves are given off from lambda #a4e mu to lambda #j4baf mu with the exception of the short band 7lambda #j4fg mu to lambda #j4ea mu7 in the visible1 and it is highly probable that no radiation is given off with wave-lengths longer than lambda #a4e mu4 ,the firefly light remains1 then1 #ajj per cent4 efficient1 differing from all our artificial sources of light1 the best of which does not approach this value4 ,as ,langley and ,very express it in the title to their paper1 it is the cheapest form of light1 not cheapest in the sense of that we can reproduce it commercially at less cost than other lights1 but cheaper in the sense that it is the most economical in the energy radiated4 ,this energy is all light and no heat4 ,cold light has actually been developed by the firefly and concerning which we know of nothing to prevent our successfully imitating4 ,illustration3 ,,fig4 #aa4--,spectral energy curves of various fireflies and the carbon glow lamp 7after ,coblentz74 ,i have already pointed out that we may also consider the efficiency of a light in relation to the sensibility of our own eye4 ,that is1 we take into account not only the energy distribution in the spectrum of the light but also the fact that different wave-lengths of an equal energy spectrum affect our eye very differently4 ,as the normal light-adapted eye is most sensitive to yellow green of lambda #j4efe mu1 monochromatic light of this wave-length will appear much brighter than monochromatic light of any other wave-length with the same energy4 ,monochromatic light of lambda #j4efe mu will then be the theoretically most efficient possible1 when we consider the energy radiated in relation to the sensitivity of our eye4 ,this is the usual method of determining the luminous efficiency of artificial lights and is obtained from a knowledge of the radiated energy and the visual sensibility4 ,reduced luminous efficiency light 7radiated energy x visual sensibility7 or luminosity _/ total radiated energy4 ,illustration3 ,,fig4 #ab4--,visibility curves of various investigators obtained by different methods 7after ,hyde1 ,forsyth and ,cady74 ,illustration3 ,,fig4 #ac4--,luminous efficiency of the #d-watt carbon glow lamp1 shaded area _/ total area 7after ,ives and ,coblentz74 ,illustration3 ,,fig4 #ad4--,luminous efficiency of the firefly1 shaded area _/ total area 7after ,ives and ,coblentz74 ,the spectral energy curve for the firefly has been worked out by ,ives and ,coblentz 7#aiaj71 using a photographic method in which the intensities of different wave-lengths of the firefly 7,photinus pyralis7 light is compared with that of a carbon glow lamp by measuring theamount of photochemical change produced on panchromatic photographic plates4 ,fig4 #aa gives the energy curves of various fireflies and the carbon glow lamp in the same spectral region4 ,the visual sensibility curve used by ,ives and ,coblentz is that of ,nutting 7#aijh1 #aiaa71 based on ,konig's data4 ,it is reproduced in ,fig4 #f4 ,the latest visibility curve is that of ,hyde1 ,forsyth and ,cady 7#aiah71 reproduced in ,fig4 #ab4 ,it is based on observations of twenty-nine individuals4 ,as individuals vary considerably in their sensibility to different wave-lengths1 the visibility curve represents an average1 but it is the only standard we have with which to evaluate the energy we call light4 ,color-blind individuals would have a visibility curve very different from normal individuals4 ,composite curves showing the luminous efficiency of the #d-watt carbon glow lamp and the firefly1 both in relation to visibility1 are given in ,figs4 #ac and #ad1 respectively4 ,in these figures the luminous efficiency is the shaded area _/ total area1 #j4dc per cent4 for the carbon glow lamp and #ii4e per cent4 for the firefly1 these numbers representing the relative amounts of light 7measured on a photometer7 for equal amounts of radiated energy--a striking illustration of the wastefulness of artificial methods of light production4 ,from the specific consumption of the tungsten lamp 7#a4f watts per spherical candle7 and the mercury arc 74#ee watts per spherical candle7 we obtained by comparison with the carbon filament that their luminous efficiencies are #a4c and #c4h per cent4 ,the most efficient artificial illuminant therefore has about #d per cent4 of the luminous efficiency of the firefly4 ,this is calculated to be 4#jb watts per candle4 ,more recent determinations 7,coblentz1 #aiab71 using a new sensibility curve of ,nutting's 7#aiaa7 for a partially light-adapted eye1 give the reduced luminous efficiency as #hg per cent4 for ,photinus pyralis1 #hj per cent4 for ,photinus consanguineus and #ib per cent4 for ,photuris pennsylvanica4 ,illustration3 ,,fig4 #ae4--,spectral energy1 luminosity and visibility curves 7after ,gibson and ,mc,nicholas7 ,a4 ,spectral energy curve of ,hefner lamp4 ,b4 ,spectral energy curve of acetylene flame4 ,c4 ,spectral energy curve of tungsten 7gas-filled7 glow lamp4 ,d4 ,spectral energy curve of black body at #ejjj deg4 absolute 7sunlight74 ,e4 ,spectral energy curve of blue sky4 ,hg4 ,spectral energy curve of ,heraeus quartz mercury lamp4 ,lv4 ,visibility curve for human eye4 ,la4 ,luminosity of ,hefner lamp4 ,le4 ,luminosity of blue sky4 ,the luminous efficiencies of various forms of artificial illuminants have been calculated by ,ives 7#aiae7 and are given together with that of the firefly in ,table #f4 ,fig4 #ae gives spectral energy curves for various illuminants reduced to #ajj at lambda 4#eij mu1 luminosity curves for the ,hefner lamp and blue sky1 and a visibility curve worked out by ,coblentz and ,emerson 7#aiag7 from observations on #acj individuals4 ,,table #f ,luminous ,efficiencies of ,various ,illuminants ---------------------------------------- -------------------------------- ,efficiency ,illuminant and ,commercial ,lumens 7visible commercial description rating per radiation x watt visual sensibility _/ total radiation7 ---------------------------------------- -------------------------------- ,carbon incandescent lamp #d watts per mean #b4f #j4jjdb oval anchored 7treated7 horiz4 c4 filament ,tungsten incandescent #a4be watts per mean #h4j 4#jac lamp1 vacuum type horiz4 c4 ,mazda1 type c #fjj ,c4 ,p4 #bj amp41 #ai4f 4#jcb #j4e w4 p4 c4 ,series type ,c4 ,carbon arc 7open7 #i4f amp4 clear globe #aa4h 4#jai ,open arc1 yellow flame1 #aj amp4 ,d4 ,c4 #dd4g 4#jgb inclined trim ,quartz mercury arc #agd-aig volt1 #d4b amp4 #db4j 4#jfh ,glass mercury arc #dj-gj volt1 #c4e amp4 #bc4j 4#jcg ,nernst lamp #d4h 4#jjgg ,acetylene #a ,l per hr4 consumption 4#fg 4#jjaa ,petroleum lamp 4#bf 4#jjjd ,open flame gas burner ,bray #f high pressure 4#bb 4#jjjcf ,incandescent gas lamp1 4#cej lumens per #a4b 4#jjai low pressure ,b4 ,t4 ,u4 per hr4 ,incandescent gas lamp1 4#egh lumens per #b4j 4#jjcb high pressure ,b4 ,t4 ,u4 per hr4 ,firefly #fbi4j 4#if ---------------------------------------- -------------------------------- ,the firefly light by the above method of calculating efficiency is not #ajj per cent4 efficient because its maximum 7lambda #j4efg mu7 does not correspond with the maximum sensibility of the eye 7lambda #j4efe mu71 but taking into consideration also other effects of color1 the firefly light would be a still more inefficient and trying one for artificial illumination1 as all objects would appear a nearly uniform green hue4 ,indeed the distortion would be even greater than with the mercury arc1 whose objectionable green hue is so well known4 ,we may say1 therefore1 that the firefly has carried the striving for efficiency too far to be acceptable to human use2 it has produced the most efficient light known1 as far as amount of light for expenditure of energy is concerned1 but has produced it at the 7inevitable7 expense of range of color4 ,the most efficient light for human use1 taking into account both color and energy-light relationships1 would be a light similar to the firefly light containing no radiation beyond the visible spectrum1 but differing from it by being white4 7,ives1 #aiaj47 ,although the spectral energy curve for ,cypridina light has not been worked out1 it will be noted that the ,cypridina spectrum is much longer than that of the firefly1 more nearly approaching the spectrum of an incandescent solid giving white light4 ,it approaches1 but does not attain the ideal4 ,although ,muraoka 7#ahif7 and ,singh and ,maulik 7#aiaa7 have described radiations coming from fireflies which would pass opaque objects and affect a photographic plate1 and ,dubois reports the same from bacteria1 the existence of such radiation has been denied by ,suchsland 7#ahih71 ,schurig 7#aija7 and ,molisch 7#aijd book74 ,the experiments of ,molisch on luminous bacteria are of greatest interest1 for they are very carefully controlled and show without a doubt that black paper or ,zn1 ,al1 or ,cu sheet will allow no rays from these organisms to pass that will affect a photographic plate1 even after several days' exposure4 ,the visible light of luminous bacteria will affect the plate after one second exposure4 ,moreover1 ,molisch has pointed out the errors of those who claim to have found penetrating radiation in luminous forms4 ,it seems that certain kinds of cardboard1 especially yellow varieties1 or wood1 will give off vapors that affect the photographic plate4 ,the action is especially marked with damp cardboard at a temperature of #be deg4-#ce deg4 ,c41 and ,dubois and ,muraoka must have used such cardboard to cover their plates4 ,a piece of old dry section of beech or oak trunk1 placed on a photographic plate for #ae hours in a totally dark place1 will register a beautiful picture of the annual rings of growth1 medullary rays1 junction of bark and wood1 etc4 ,russell 7#ahig7 had previously found that many bodies1 both metals and substances of organic origin 7gums1 wood1 paper1 etc471 placed in contact with photographic plates1 would affect them1 and concluded that vapors and not rays were the active agents4 ,as a dry piece of wood has a very definite smell1 there is something given off which can affect our nose and there is no reason why it should not change1 by purely chemical action1 the photographic plate4 ,this action of wood on the plate is prevented by interposing a sheet of glass4 ,frankland 7#ahih7 has described similar vapors coming from colonies of ,bacillus proteus vulgaris and ,b4 coli communis which affect a photographic plate laid directly over the colonies in an open petri dish4 ,there is no effect if the glass cover of the petri dish is between plate and bacteria4 ,there is1 then1 no specific emission of ,x-rays or similar penetrating radiation from luminous tissues which will affect the photographic plate through opaque screens4 ,a similar conclusion is reached if we attack the problem in another way4 ,x-rays and radium rays 7,becquerel rays7 cause fluorescence of ,zn,s1 barium platinocyanide1 willemite 7,zn#b,si,o#d71 and calcium tungstate4 ,coblentz 7#aiab7 showed that the firefly will cause no fluorescence of a barium platinocyanide screen and ,i have been unable to detect fluorescence of zinc sulphide1 barium platinocyanide1 zinc silicate 7willemite7 or calcium tungstate shielded from ,cypridina light by black paper1 although the light of this organism is quite bright enough to cause phosphorescence of zinc sulphide without the black paper4 ,the samples of the above four substances all showed fluorescence in presence of radium rays1 but only the ,zn,s phosphoresces after exposure to light rays1 although the willemite was phosphorescent after exposure to the ultra-violet4 ,while photometry at low intensities is a difficult procedure at best1 if the light varies in intensity or is a flash1 accurate measurements become well-nigh impossible4 ,the figures given for intensity of animal luminescence must1 therefore1 be accepted with a realization of the difficulties of measurement4 ,by candle is meant the international candle1 unless otherwise specified1 equal to #a4aa ,hefner candles 7,h4 ,k47 #j4a pentane lamp and #j4ajd carcel units4 ,it is a measure of intensity4 ,amount of light1 or light flux1 measured in lumens1 is that emitted in a unit solid angle 7area_/r#b7 by a point source of one candle-power4 ,one candle-power emits #dpi lumens4 ,the latest figure for the mechanical equivalent of light at lambda 4#eff is 4#jjae watt 7,hyde1 ,forsyth and ,cady1 #aiai71 i4e41 #a lumen 4#jjae watt4 ,one watt is #ajg ergs 7one joule7 per second4 ,the illumination 7of a surface7 is that given by one candle at one metre1 the candle metre 7,c4,m47 or lux4 ,the surface then receives one lumen per square metre4 ,a metre kerze 7,m4,k47 is the illumination given by one ,hefner candle at one metre distance4 ,the brightness of a surface is measured in lamberts or millilamberts4 ,a lambert is the brightness of a perfectly diffusing surface radiating or reflecting one lumen per square cm4 ,a millilambert is #a_/ajjj lambert4 ,for further definitions the reader is referred to the reports of the committee on nomenclature of the ,illuminating ,engineering ,society4 ,dubois 7#ahhf7 states that one of the prothoracic organs of ,pyrophorus noctilucus has a light intensity of #a_/aej ,phoenix candle of eight to the pound 7probably about equivalent to #a_/aej candle7 and that #cg or #ch beetles 7each using all three light organs7 would produce light equivalent to one ,phoenix candle4 ,langley 7#ahij7 found that to the eye the prothoracic organ of ,pyrophorus noctilucus gave one-eighth as much light as an equal area of a candle and the actual candle-power of the insect was #a_/afjj candle4 ,it may be remarked in passing how widely divergent these observations are4 ,for the flash of the firefly 7,photinus pyralis7 ,coblentz 7#aiab7 found variation from #a_/ej to #a_/djj candle1 the predominating values being around #a_/djj candle4 ,a continuous steady glow is sometimes obtained from this insect and it proved to be of the order of #a_/ej1jjj candle4 ,steady sources of light can be more easily measured and we have two records of the light intensity from luminous organisms with continuous light4 ,one of these is a fish1 ,photoblepharon palpebratus1 with a large luminous organ under the eye1 of flattened oval shape1 #aa x #e mm41 which glows continuously without change of intensity4 ,the organ can be darkened by a screen similar to an eyelid which pulls up over it4 ,steche 7#aiji7 reports the intensity to be 4#jjbd ,m4,k4#c #c ,the metre-kerze is a unit of illumination1 not of intensity1 and is incorrectly used by ,steche4 ,luminous bacteria probably glow with less intensity than any other organism4 ,the light from a single organism cannot be seen but that from a colony is visible to the dark-adapted eye4 ,even so we must remember that the eye is an exceedingly delicate instrument which can detect very small energy changes4 ,the minimum radiation visually perceptible has been calculated by ,reeves 7#aiag7 to be in the neighborhood of #ah x #aj-aj ergs per second and the light from a small colony of luminous bacteria represents little more radiation than this4 ,lode 7#aijd1 #aijh71 by a modified grease spot photometer method1 ascertained that the light of his brightest bacterial colony of ,vibrio rumple had an intensity of #g4he x #aj-aj ,h4,k4 per sq4 mm4 or #j4ghe ,h4,k4 per #ajjj sq4 metres 7#j4efb ,german-normal candles per #ajjj sq4 metres74 ,in round numbers this is about one ,german-normal candle per #bjjj sq4 metres1 or two to three times this area for the light from an ordinary stearin candle4 ,lode calculated that the dome of ,st4 ,peter's at ,rome1 if covered with bacteria1 would give little more light than a common stearin candle4 ,an ordinary room of #ej sq4 metres wall and ceiling area would give out only #j4jci ,german-normal candle4 ,it does not seem likely that luminous bacteria will ever come into vogue for illuminating purposes4 ,friedberger and ,doepner 7#aijg7 by a photographic method1 not entirely free from error1 found that one square millimetre of lighting surface of a bouillon culture of photobacteria gave #f4h x #aj-i ,german-normal candles1 about ten times ,lode's value4 ,even at this rate commercial lighting by luminous bacteria does not appear a promising field for investors4 ,to sum up1 we may say that light from animal sources is in no way different from light of ordinary sources1 except in intensity and spectral extent4 ,it is all visible light1 containing no infra-red or ultra-violet radiation or rays which are capable of penetrating opaque objects4 ,it is not polarized as produced1 but may be polarized by passing through a ,nichol prism4 ,like ordinary light1 animal light will also cause fluorescence and phosphorescence of substances1 affect a photographic plate1 cause marked heliotropism of plant seedlings 7,nadson1 #aijc7 and stimulate the formation of chlorophyll 7,issatschenko1 #aijc1 #aijg74 ,because of the weakness of bacterial light1 etiolated seedlings do not become green to the eye 7,molisch1 #aiab book71 but a small amount of chlorophyll is formed which can be recognized by the spectroscope because of its absorption bands4 ,,chapter ,,iv ,,structure ,,of ,,luminous ,,organs ,the production of light is the converse of the detection of light4 ,in the first case chemical energy is converted into radiant energy2 in the second case radiant energy is converted into chemical energy4 ,the lantern of the firefly is an organ of chemi-photic change2 the eye is an organ of photo-chemical change4 ,while it is theoretically probable that all reactions which proceed in one direction under the influence of light1 will proceed in the opposite direction with the evolution of light1 the formation of luciferin from oxyluciferin 7described in ,chapter ,,vi7 is the only one definitely known4 ,perhaps we may place in this category also the instances of photoluminescence1 but the chemical reaction involved cannot be pointed out4 ,we know of no animal whose eyes1 the organs1 par excellence1 of photochemical change1 give off light in the dark4 ,all cases of luminous eyes have been conclusively shown to be purely reflection phenomena4 ,the eyes of a cat only glow if some stray light is present which may enter and be reflected out again4 ,photochemical reactions and chemiluminescent reactions do have this in common1 however1 that they are largely but not exclusively oxidations4 ,whether all photochemical changes in the eyes in animals require oxygen or not1 is unknown1 but all animal light-producing reactions1 without exception1 are oxidations1 and light is only produced if oxygen is present4 ,some material is oxidized4 ,in general1 we may divide luminous organisms into two great classes according as the oxidizable material is burned within the cell where it is formed or is secreted to the exterior and is burned outside--intracellular and extracellular luminescence4 ,many animals with intracellular luminescence have quite complicated luminous organs4 ,it is an interesting fact that a great similarity may be observed between the evolution of the complex organs of vision and of these complicated organs4 ,in the simplest unicellular forms certain structures within the cell serve as the photochemical detectors of light1 while in luminous protozoa1 similarly1 granules scattered throughout the cell are oxidized with light production4 ,in the higher forms the eye contains groups of photosensitive cells connected with afferent nerves1 lenses1 and accessory structures for properly adjusting the light1 while luminous organs contain groups of photogenic cells in connection with efferent nerves1 lenses1 and accessory structures for properly directing the light4 ,it is interesting to note that in the two groups where the eye has attained its highest development1 the cephalopods and vertebrates1 here also the luminous organ is found in greatest complexity and perfection4 ,in intermediate stages of evolution the eye and luminous organ so closely approach each other in structure that it is still a mooted question whether certain organs found in worms and crustacea are intended for receiving or producing light4 ,we may also divide luminous forms into two groups according as the oxidation of luminous material goes on continuously1 independently of any stimulation of the organism2 or is intermittent1 oxidation and luminescence occurring only as a result of stimulation1 using the word stimulation in the same sense in which it is used in connection with nerve or muscle tissue4 ,bacteria1 fungi1 and a few fish produce light continuously and independently of stimulation4 ,its intensity varies only over long periods of time and is dependent on the nature of the nutrient medium or general physiological condition of the organism4 ,all other forms give off no light until they are stimulated4 ,stimulation may of course come from the inside 7nerves7 or outside4 ,only under unfavorable conditions1 such as will eventually lead to the destruction of the luminous cells1 do these forms give off a continuous light4 ,this has often been spoken of as the death glow1 and is to be compared with rigor in muscle tissue4 ,some of the fish which produce a continuous light possess a movable screen similar to an eyelid which can be drawn across the organ1 thus shutting off the light1 so that the animal appears to belong to the group which flashes on stimulation4 ,this is true of ,photoblepharon1 while ,anomalops can rotate the light organ itself downward1 so as to bring the lighting surface against the body wall and thus cut off the light 7,steche1 #aiji74 ,other fish 7,monocentris7 are unable to turn off their light4 ,animals which flash spontaneously on stimulation through nerves from within1 possess a very varied rhythm4 ,the different species of fireflies can be distinguished by the character of their flashing 7,mc,dermott1 #aiaj-ag2 ,mast1 #aiab74 ,fig4 #af shows the method of flashing of some common eastern ,north ,america species4 ,the glowworm light lasts for many seconds and then dies out4 ,this interval of darkness persists for some minutes and is then followed by another period of glowing4 ,some fireflies have a light which may be described as partially intermittent4 ,it lasts for hours1 but may become more dim or be intensified on stimulation4 ,illustration3 ,,fig4 #af4--;,chart showing relative intensities and durations of flashes of ,american fireflies 7after ,mc,dermott74 ,one cm4 vertically approximately #j4jb candle power2 one cm4 horizontally approximately one second4 ,the flash of the males 7male7 is at the left2 that of females 7female7 at right of chart4 ,some forms only produce light at certain seasons of the year4 ,according to ,giesbrecht 7#ahie7 this is true of the copepods1 which only light in summer and autumn1 and according to ,greene 7#ahii7 in the toad-fish2 ,porichthys1 which can only be stimulated to luminesce during the spawning season in spring and early summer4 ,some animals possess a periodicity of luminescence4 ,they only luminesce at night and fail to respond to stimulation or are difficult to stimulate during the day4 ,bright light has an inhibiting effect4 ,perhaps correlated with this is the fact that most luminous forms are strongly negatively heliotropic4 ,fireflies lie hidden in the day1 to appear about dusk and the ostracod crustacean1 ,cypridina1 is difficult to obtain on moonlight nights4 ,the ,ctenophores were the first forms in which the inhibiting effect of light was noticed4 ,this was described by ,allman 7#ahfb7 and has been confirmed by a number of observers1 especially ,peters 7#aije74 ,massart found that ,noctiluca was difficult to stimulate during the day and ,ceratium1 according to both ,zacharias 7#aije7 and ,moore 7#aijh71 only luminesces at night1 or if kept in darkness1 for some little time4 ,crozier#d finds a persistent day-night rhythm of light production when ,ptychodera1 a balanoglossid1 is maintained for eight days in continued darkness4 ,the animal is difficult to stimulate during the period which corresponds to day and luminesces brilliantly and at the slightest touch during the period which corresponds to night4 ,on the other hand1 a great many forms are able to luminesce quite independently of previous illumination4 ,according to ,crozier#d ,chaetopterus luminescence is not affected by an exposure to #cjjj metre-candles for six hours4 #d ,private communication4 ,in the case of animals with extracellular luminescence we may speak of luminous secretions and true luminous glands4 ,a large number of forms possess luminous glands or gland cells1 including some of the medusae1 the hydroids 7probably71 the pennatulids 7871 the molluscs 7,pholas and ,phyllirhoe7 7probably71 some cephalopods 7,heteroteuthis and ,sepietta71 most annelids1 ostracods1 copepods1 some schizopods 7,gnathophausia7 and decapod 7,heterocarpus and ,aristeus7 crustaceans1 all myriapods1 and the balanoglossids4 ,the remaining organisms burn their material within the cell4 ,these include the bacteria1 fungi1 protozoa1 some medusae 7871 ctenophores 7probably71 most cephalopods1 a few annelids 7,tomopterus 78771 ophiuroids 7871 some schizopod 7,nyctiphanes1 ,euphasia1 ,nematocelis1 ,stylochiron7 and decapod 7,sergestes7 crustacea1 all787 insects1 ,pyrosoma1 and fishes 7selachians and teleosts74 ,it is among this latter type that the most complicated luminous organs have been developed4 ,while a description of all the types of luminous organs and luminous structures cannot be attempted here 7excellent descriptions have been given by ,dahlgren and ,mangold7 it is necessary to understand the structural conditions in a few of the forms whose physiology has attracted most attention4 ,luminous bacteria are so small that the light from a single individual cannot be seen4 ,it is almost impossible to make out structural differences within the cell and we cannot definitely state in just what special region1 if any1 the luminescence is produced4 ,we do know that the light is intracellular and that filtration of the bacteria from their culture medium gives a dark sterile filtrate absolutely free from any luminous secretion4 ,among protozoa1 in certain forms at least1 it is easy to observe that luminescence is connected with globules or granules which were considered by the earlier observers to be oil droplets4 ,thus1 in ,noctiluca 7,figs4 #ag and #ah71 when the animal is violently stimulated or in the presence of reagents which slowly kill it1 the whole interior appears a mass of starry points of light which can be traced to minute granules along the strands of protoplasm 7,quatrefages1 #ahej74 ,illustration3 ,,fig4 #ag4--,noctiluca miliaris1 showing photogenic granules in cytoplasm4 n1 nucleus2 c1 cytoplasmic strands containing photogenic 7large7 and other 7small7 granules2 p1 pharynx2 f1 flagellum2 o1 oral groove2 t1 tentacle2 s1 spines at base of tentacle2 v1 vacuoles4 ,drawn by ,e4 ,b4 ,harvey4 ,illustration3 ,,fig4 #ah4--,noctiluca miliaris as it appears during luminescence 7after ,quatrefages74 ,upper left and middle1 low power2 below1 high power2 upper right1 a crushed fragment still luminescent4 ,turning to the multicellular forms1 we find the simplest development of luminosity in those animals which possess gland cells producing a luminous secretion4 ,these cells may be scattered over the surface of the animal as in ,chaetopterus 7,fig4 #ai7 or ,cavernularia1 or restricted to certain areas ,pholas1 7,fig4 #ai71 or more definitely localized to form an isolated group of gland cells as in ,cypridina4 ,true multicellular glands also occur4 ,in every case1 however1 we find that the luminosity of these uni- or multicellular glands is connected with the presence of granules4 ,they are often spoken of as luciferine granules1 although it is not certain whether they are made up of luciferin or luciferase 7see ,chapter ,,iv7 or both4 ,they are most similar to the zymogen granules found so abundantly in gland cells and thought to be the precursors of various enzymes4 ,according to ,dahlgren 7#aiae71 the luciferine granules stain blue-black by iron haematoxylon after fixation at the boiling point1 and photogenic cells can be detected by this method of selective staining4 ,dubois 7#aiad1 book71 who regards them as examples of bioprotein1 comparable to the chondriosomes and handed on from one generation to another1 gives them the name of vacuolides or macrozymases4 ,in some forms he has described their transformation into crystals and believed at one time that animal light was a crystalloluminescence4 ,his figures of the crystal transformation are not very convincing4 ,pierantoni 7#aiae7 has considered the granules to be symbiotic luminous bacteria1 but this is certainly not the case4 ,illustration3 ,,fig4 #ai4--;,diagram of ,pholas 7right7 and ,chaetopterus 7left7 to show distribution of luminous areas 7after ,panceri74 ,the light of ,chaetopterus comes from a material mixed with a mucous secretion formed over almost the whole body surfaces of the animal4 ,a section of the epithelium shows large mucous-producing cells and smaller granule-containing light cells 7,fig4 #bj74 ,these appear to be under nervous control1 as a strong stimulation in one part of the body causes luminescence which spreads over the whole surface of the worm4 ,the animal becomes fatigued rather readily1 however4 ,in the pennatulids1 such as ,cavernularia1 we have also the formation of a luminous secretion over the whole surface of the body and the individual animals in this colonial form are also connected with nerves4 ,a stimulation in any local region1 as ,panceri 7#ahgb7 first showed 7,fig4 #ba71 will cause a wave of luminosity to spread from this point until it extends over the whole surface of the colony4 ,in ,pennatula the rate of this luminous wave is about #e cm4 per second4 ,illustration3 ,,fig4 #bj4--,sectional view of the luminous epithelium of ,chaetopterus 7after ,dahlgren74 cu1 cuticle2 l4 c41 light cells1 some showing discharge of secretion2 d4 l4 c41 discharged and emptied light cells2 m4 c41 mucous cells4 ,illustration3 ,,fig4 #ba4--;,diagram of ,pennatula1 showing by arrows the course of a wave of luminosity which spreads over the colony from the point stimulated 7s7 7after ,panceri74 ,pholas dactylus possesses similar light cells to those of ,chaetopterus1 but they are restricted to narrow bands on the siphon and mantle and a pair of triangular spots near the retractor muscles4 ,nerves pass to the luminous regions4 ,in many luminous animals the light secretion formed over the surface of the body is small in amount and adheres to the animal because it is embedded in the mucous skin secretions4 ,in those forms which possess a true localized light gland the luminous secretion when expelled into the sea water 7if the animal be a marine form7 may persist as a luminous streak for some time and exhibit diffusion and convection movements4 ,the most beautiful examples of luminous secretions are found among the ostracod crustacea4 ,illustration3 ,,fig4 #bb4--,luminous gland of ,cypridina hilgendorfii 7after ,yatsu74 #b1 longitudinal section4 #d1 transverse section4 ,illustration3 ,,fig4 #bc4--,single enlarged gland cell of ,cypridina 7after ,dahlgren74 ,p1 nucleus and plasmasome2 ,c1 cytoplasm2 ,f1 secretion fibrils2 ,d1 reservoir duct filled with large yellow granules2 ,o1 valve-like outer opening of cell at surface of body4 ,in ,cypridina hilgendorfii the luminous gland is situated on the upper lip near the mouth4 ,it is made up of elongate 7some #j4g mm4 in length71 spindle-shaped cells1 each one of which opens by a separate pore with a kind of valve4 ,the openings are arranged on five protuberances4 ,muscle fibres pass between the gland cells in such a way that by contracting the secretion can be forced out4 ,in the sea water the secretion luminesces brilliantly and the ,japanese call these forms umi hotaru1 or marine fireflies4 ,fig4 #bb is a diagram showing the structure4 ,watanabe 7#ahig71 who first studied this form1 and also ,yatsu 7#aiag7 have described two kinds of granule-containing cells1 one with large yellow globules1 #d-aj mu in diameter 7,fig4 #bc71 the other with small colorless granules #j4e1 in diameter4 ,i have observed in the living form these two types and also large colorless globules of the same size as the yellow globules4 ,all dissolve when extruded into the sea water4 ,dahlgren#e has described from sections four types of cells containing 7#a7 large globules1 7#b7 small granules1 7#c7 a fat-like material1 7#d7 a mucous material4 ,just what the significance and nature of these types of substance is cannot be stated at present4 ,at least one1 probably two1 are concerned in light production4 ,the others may possibly form digestive fluids which act on the food of the animal4 #e ,private communication soon to be published4 ,turning now to the animals possessing light cells with intracellular luminescence we find in general that such light cells are localized to form definite light organs and that these may be single1 as in the common fireflies1 paired1 as the prothoracic light organs of ,pyrophorus1 or scattered over the surface of the body1 as in so many shrimps1 cephalopods and fishes1 when they are often called photophores4 ,the light cells proper are often associated with reflectors1 lenses1 opaque screens and color screens4 ,illustration3 ,,fig4 #bd4--;,distal portion of malpighian tubule of ,bolitophila1 showing modification to form photogenic organ 7after ,wheeler and ,williams74 ,,mt#a1 ,,mt#d1 malpighian tubules forming photogenic organ2 ,r1 reflector2 ,m1 muscle2 ,t1 trachea4 ,the insects possess the simplest types of intracellular light organs1 a mass of photogenic cells1 which1 in the common firefly 7a lampyrid beetle7 of ,eastern ,north ,america1 has probably been developed from the fat body1 while in the ,new ,zealand glowworm1 the larva of a tipulid fly 7,bolitophila luminosa71 part of the ,malpighian tubule cells have acquired photogenic power 7,wheeler and ,williams1 #aiae74 ,this is illustrated in ,fig4 #bd4 ,the photogenic organ of the firefly is made up of two kinds of cells1 a dorsal mass of small cells several layers deep1 the reflector layer1 and a ventral mass of large cells with indistinct boundaries1 the photogenic layer 7,fig4 #be74 ,the photogenic cells contain a mass of granules1 spherical in the male and short rods in the female4 ,the photogenic cells are divided into groups by large tracheal trunks which pass into the light organ and branch to form tracheoles connected with tracheal end cells4 ,the exact distribution varies in different species1 but in all the arrangement is such as to give a very abundant oxygen supply4 ,each group of photogenic cells is surrounded by a clear ectoplasm containing no granules4 ,the tracheoles pass through this and either end openly within the photogenic cells or anastomose with tracheoles from neighboring tracheae4 ,nerves1 but no blood-vessels--which are absent in insects--enter the organ4 ,it is difficult to determine if the nerves supply the tracheal end cells or the photogenic cells4 ,illustration3 ,,fig4 #be4--,sectional view of photogenic organ of the firefly 7after ,williams71 showing reflector or crystal layer 7,u7 above and photogenic cells 7,p7 below4 ,c1 cuticula2 ,t1 trachea2 c1 capillaries of tracheal end cells2 ,h1 hypodermis2 ,,ec1 tracheal end cells2 ,n1 nerve4 ,the dorsal reflecting layer is made up of cells containing numerous minute crystals of some purin base1 either xanthin or urates1 or both4 ,they have a white milky appearance and while they are certainly not good reflectors in the optical sense1 they do act as a white background1 scatter incident light1 and partially prevent its penetration to the internal organs of the firefly4 ,although a few crystals similar to those of the reflector layer are found in the photogenic cells and in other cells of the body1 it is known that the photogenic cells are not transformed into the reflector cells4 ,the two layers are distinct and permanent from an early stage in development4 ,curiously enough1 the light organ of the larva of the firefly 7glowworm7 is quite distinct from that of the adult4 ,like so many other structures in insects1 the adult organ is developed anew from potential photogenic cells during the pupal period4 ,even the egg of the firefly is luminous and glows with a steady light1 and during the pupal period light may sometimes be seen coming from the thoracic region4 ,in the firefly there is no true lens1 the light merely shining through the cuticle which is transparent over the light organ1 whereas over the rest of the body it is dark and pigmented4 ,in the deep sea shrimp1 ,acanthephyra debelis1 with light organs scattered over the surface of the body1 the cuticle covering the light organ forms a concavo-convex lens1 behind which are the photogenic cells 7,kemp1 #aiaj74 ,as may be seen from ,fig4 #bf1 the lens is made up of three layers which suggests that it may be corrected for chromatic aberration--a veritable achromatic triplet4 ,in an allied form1 ,sergestes 7,fig4 #bg71 the lens is of two layers and double convex4 ,optical studies of these lanterns have been made by ,trojan 7#aijg74 ,the course of the light rays is shown in ,fig4 #bh4 ,the lens of these organs is also bluish in color which suggests that they may serve also as color filters4 ,behind the photogenic cells is a mass of connective tissues through which enters the nerve1 for the light of these organs is under the control of the animal and may be flashed at will4 ,illustration3 ,,fig4 #bf4--,sectional view of photogenic organ of ,acanthephyra debilis 7after ,kemp74 n1 nerve2 s4 l41 sheathing layer of cells2 g1 cone of refractive granules at end of nerve strand2 c1 cellular layer2 i4 l41 m4 l41 o4 l41 inner1 middle and outer layer of lens4 ,illustration3 ,,fig4 #bg4--,sectional view of photogenic organ of ,sergestes prehensilis 7after ,terao74 bm1 basement membrane2 cs1 connective strands of photogenic layer2 hy1 hypodermis2 l#a1 l#b1 l#c1 layers of lens2 le1 lens epithelium2 n1 nerve2 ph1 photogenic cells2 pi1 pigment layer2 r1 reflector2 th1 theca4 ,illustration3 ,,fig4 #bh4--;,diagram of photogenic organ of ,nyctiphanes ,conchii1 to show pathways of light rays arising in the light cell layer 7after ,trojan74 p1 pigment2 ri1 inner reflector2 lp1 light cells2 rf1 refractor2 f1 focus2 l1 lens2 ,a-,a1 axis2 a#a-;a#d1 b#a-;b#d1 light rays reflected from ri2 c#a-;c#d1 light rays passing directly outward2 d#a-;d#i and e#a-;e#i1 light rays which have passed refractor and lens respectively4 ,all gradations in complexity of light organs may be found from the condition in the shrimp just described to that found among the squid and fish4 ,figs4 #bi and #cj are sections of two of the more complicated types found in squid4 ,the explanation given to the various structures is that of ,chun 7#aijc7 to whom we are indebted for a careful histological investigation of these forms4 ,it will be noted that in addition to photogenic and lens tissues there are various types of reflector cells and a line of pigment about the whole inner surface of the organ to effectively screen the animal's tissues from the light4 ,in one form 7,fig4 #cj7 chromatophores are found about the region where the light is emitted and these no doubt serve as color filters4 ,there are also an abundant blood supply and nerves passing to the organ4 ,figs4 #cj and #ca are sections through light organs of fishes4 ,we thus see that light organs may be very simple and also very complicated4 ,the latter must have evolved from the former1 although it is not always possible to point out the intermediate stages4 ,it is not within the scope of this book to discuss bioluminescence in its evolutionary aspects4 ,it may be worth while1 however1 to point out briefly what is known concerning the use of the light to the animal4 ,there are four possibilities4 ,illustration3 ,,fig4 #bi4--,sectional view of photogenic organ of a squid1 ,abraliopsis 7after ,chun47 refl#a1 refl#b1 reflectors2 lac41 lacunar spaces2 chr41 pigment screen of chromatophores2 chr4#a1 chromatophore2 phot41 photogenic cells2 l1 lens2 co41 cuticle2 v1 blood vessel2 fibr41 connective tissue4 7#a7 ,the light may be of no use whatever1 purely fortuitous1 an accompaniment of some necessary or even unnecessary chemical reaction4 ,this appears to be the case in the luminous bacteria and fungi and perhaps the great majority of forms which make up the marine plankton1 ,noctiluca1 dinoflagellates1 jelly-fish1 ctenophores and even the sessile sea pens4 ,illustration3 ,,fig4 #cj4--,sectional view of photogenic organ of a squid1 ,calliteuthis 7after ,chun74 phot41 photogenic cells2 l1 l#a1 lens2 n1 nerve2 spec41 ,spiegel2 pg41 pigmented screen2 c4 fusif41 spindle-shaped reflector cells2 chr41 chromatophore color screen4 ,illustration3 ,,fig4 #ca4--,sectional view of photogenic organ of a fish1 ,stomias 7after ,brauer74 p1 pigment screen2 dr1 dr#a1 photogenic gland cells2 l1 lens4 ,we know that luminous bacteria occasionally lose the power of lighting and that on certain culture media they develop as non-luminous forms4 ,luminescence is not indispensable to them4 ,the same is true of some of the fungi but ,noctiluca and other animals are not known in a non-luminous condition1 although we can see no definite value to the organism of this power of luminescence4 ,illustration3 ,,fig4 #cb4--,sectional view of photogenic organ of a fish1 ,argyrophelecus affinis 7after ,brauer74 p1 pigmented screen2 dr41 photogenic cells2 r1 r#a1 reflector82 l1 lens82 s1 sclera2 g1 connective tissue4 ,in the case of sea pens1 however1 we might suppose that the light acts as an attraction to small organisms on which the sea pen feeds1 although these creatures only luminesce when stimulated in some way1 which rather detracts from the above suggestion4 7#b7 ,the light may act as a warning to scare away predacious animals which would otherwise feed on the luminous organism4 ,perhaps this is the case in the sea pens1 although these forms possess nematocysts which should serve as adequate protection4 ,the marine worm1 ,chaetopterus1 is brightly luminous and lives its whole life in an opaque parchment tube4 ,if this tube were torn open by a predacious form we might conceive that the attacking animal would be alarmed by the light and refrain from destroying the worm4 ,the ,chaetopterus1 however1 could not rebuild another tube and its light would only protect it in the night time4 ,these cases will suffice to indicate the difficulties and perplexities of the problem4 ,perhaps we may add one more guess and suppose that the light of certain fishes is actually for blinding or distracting their enemies or blinding the forms on which they feed4 ,until this use of luminous organs has actually been observed1 we can give little credence to it4 7#c7 ,the light may serve as a means of recognition or a sex signal to bring the sexes together for mating4 ,it would seem from the work of ,mast and of ,mc,dermott that this is the case in the common fireflies and it may be the case in the toad-fish1 ,poricthys1 which is only luminous in the spawning season and in the worm1 ,odontosyllis1 of ,bermuda1 which is brilliantly luminous while swarming when the eggs and sperm are shed4 ,it is non-luminous at other times 7,galloway and ,welch1 #aiaa47 7#d7 ,finally1 it is possible that animals with complex luminous organs1 such as squid1 fish and shrimp1 actually use these as lanterns4 ,it is significant that most of them are deep sea forms1 living in a region of perpetual darkness1 and it is perfectly logical to suppose that they make use of their light organs for illuminating purposes4 ,the whole problem of the use and purpose of luminous organs is an exceedingly complex and difficult one4 ,we have1 perhaps1 said enough to indicate this and may add that in most cases1 so far as opinion is based on actual evidence and observation1 that of the layman is of as great value as that of the scientist4 ,,chapter ,v ,,the ,,chemistry ,,of ,,light ,,production1 ,,part ,i ,two experiments1 both performed very early in the history of ,bioluminescence1 are of great importance in understanding the nature of animal light4 ,boyle 7#affg71 as already mentioned1 proved the necessity of air for the luminescence of wood and fish and ,spallanzani 7#agid7 showed that parts of luminous medusae gave no light when dried but if moistened again would emit light as before4 ,we see then1 that air 7oxygen71 water1 and some photogenic substance are necessary for the light production4 ,spallanzani's experiment1 which has been confirmed for a great many luminous forms1 shows also that animal luminescence is not a vital process1 in the same sense that the conduction of a nerve impulse is a vital process4 ,a nerve loses its characteristic property of conduction on drying or maceration while luminous cells still possess the power to luminesce after drying or maceration4 ,using the terminology of the older physiology we may say that living protoplasm is not necessary for light production4 ,the experiments of ,boyle 7#afbf-ia7 are of great interest1 especially those in which he studied the behavior of shining wood under the receiver of his air pump4 ,on ,october #bi1 #affg1 he wrote3 ,exp4 ,i43 ,having procured a ,piece of shining ,wood1 about the bigness of a groat or less1 that gave a vivid ,light1 7for rotten ,wood7 we put it into a middle sized ,receiver1 so as it was kept from touching the ,cement2 and the ,pump being set a-work1 we observed not1 during the #e or #f first ,exsuctions of the ,air1 that the splendor of the included ,wood was manifestly lessened 7though it was never at all increased27 but about the #gth ,suck1 it seemed to glow a little more dim1 and afterwards answered our ,expectation1 by losing of its ,light more and more1 as the ,air was still farther pumped out2 till at length about the #ajth ,exsuction1 7though by the removal of the ,candles out of the ,room1 and by black ,cloaths and ,hats we made the place as dark as we could1 yet7 we could not perceive any light at all to proceed from the ,wood4 ,exp4 ,,ii43 ,wherefore we let in the outward ,air by ,degrees and had the pleasure to see the seemingly extinguished ,light revive so fast and perfectly1 that it looked to us almost like a little ,flash of ,lightning1 and the ,splendor of the ,wood seemed rather greater than at all less1 than before it was put into the ,receiver4 ,boyle proved that light from the wood was able to pass a vacuum and later showed that shining fish behaved as the shining wood1 but that a piece of white hot iron would not regain its light on readmitting air to the exhausted receiver and that the iron lost its glow under the air-pump merely because it cooled off4 ,a piece of glowing coal1 however1 did lose its light in the absence of air and regained it on again admitting air1 provided the air had not been removed for too long4 ,boyle was apparently impressed with the similarity of the light giving process in glowing coal and shining wood as he draws a comparison between the two which brings out the fundamental similarity of combustion processes4 ,resemblances3 ,,vii4 ,the ,things wherein ,i observed a ,piece of shining ,wood and a burning ,coal to agree or resemble each other are principally these five3 #a4 ,both of them are ,luminaries1 that is1 give ,light1 as having it 7if ,i may so speak7 residing in them2 and not like ,looking-glasses1 or white ,bodies1 which are conspicuous only by the incident ,beams of the ,sun1 or some other luminous ,body1 which they reflect4444 #b4 ,both shining ,wood and a burning ,coal need the ,presence of the ,air 7and that too of such a ,density to make them continue shining74444 #c4 ,both shining ,wood and a burning ,coal1 having been deprived1 for a ,time1 of their ,light1 by the withdrawing of the contiguous ,air1 may presently recover it by letting in fresh ,air upon them4444 #d4 ,both a quick ,coal and shining ,wood will be easily quenched by ,water and many other ,liquors4444 #e4 ,as a quick ,coal is not to be extinguished by the ,coldness of the ,air1 when it is greater than ordinary2 so neither is a ,piece of shining ,wood to be deprived of its ,light by the same ,quality of the ,air4444 ,differences3 #a4 ,the first ,difference ,i observed betwixt a live ,coal and a shining ,wood is1 that whereas the ,light of the former is readily extinguishable by ,compression 7as is obvious in the ,practice of suddenly extinguishing a piece of ,coal by treading upon it71 ,i could not find that such a ,compression as ,i could conveniently give without losing sight of its operation1 would put out1 or much injure the ,light1 even of small ,fragments of shining ,wood4444 #b4 ,the next ,unlikeness to be taken notice of betwixt rotten ,wood and a kindled ,coal is1 that the latter will1 in a very few ,minutes1 be totally extinguished by the withdrawing of the ,air2 whereas a ,piece of shining ,wood1 being eclipsed by the ,absence of the ,air1 and kept so for a ,time1 will immediately recover its ,light if the ,air be let in upon it again within half an hour after it was first withdrawn4444 #c4 ,the next ,difference to be mentioned is1 that a live ,coal1 being put into a small close ,glass1 will not continue to burn for very many ,minutes2 but a ,piece of shining ,wood will continue to shine for some whole ,days4444 #d4 ,a fourth ,difference may be this3 that whereas a ,coal1 as it burns1 sends forth ,store of ,smoke or ,exhalations1 luminous ,wood does not so4 #e4 ,a fifth1 flowing from the former1 is1 that whereas a ,coal in shining wastes itself at a great ,rate1 shining ,wood does not4444 #f4 ,the last ,difference ,i shall take notice of betwixt the bodies hitherto compared is1 that a quick ,coal is actually and vehemently hot2 whereas ,i have not observed shining ,wood to be so much as sensibly lukewarm4 ,it should be clearly borne in mind that if we place luminous organisms1 say bacteria or fungi1 in an atmosphere devoid of oxygen and find that no light is produced1 this may merely mean that certain functions of the cell are interfered with1 including light production1 but does not necessarily indicate that oxygen is actually used up in the photogenic process4 ,if we find1 however1 that extracts of luminous cells or luminous secretions devoid of cells cease to light when the oxygen is removed and again luminesce when it is returned1 we may be quite certain that the photogenic process itself requires free oxygen4 ,as luminous extracts of fireflies1 pennatulids1 ostracods1 ,pholas and others give off no light when the oxygen is removed1 we may safely conclude that for these luminescences1 oxygen is necessary4 ,bacteria1 fungi1 and ,noctiluca1 whose light also disappears in absence of oxygen1 although they are whole cells1 we may by analogy also assume to require oxygen in the photogenic process4 ,some of the earlier workers on fireflies and ,noctiluca obtained light even after placing these organisms in absence of oxygen1 but they did not realize how low is the amount of oxygen necessary to produce light4 ,it is difficult to remove traces of oxygen from the water1 traces which are nevertheless sufficient to cause luminescence4 ,if the organisms are numerous1 as in an emulsion of luminous bacteria1 they will themselves use up all the oxygen and the liquid soon ceases to glow except at the surface in contact with air4 ,we may gain an idea of the amount of oxygen necessary for luminescence from an experiment of ,beijerinck 7#aijb74 ,he mixed luminous bacteria with an emulsion of clover leaves containing chloroplasts and kept the two in the dark until all the oxygen was used up and the bacteria ceased to glow4 ,if now a match was struck for a fraction of a second1 sufficient oxygen was formed by photosynthesis to cause the bacteria to luminesce for a short time4 ,exact figures on the minimal concentration of oxygen for luminescence cannot be given4 ,the luminescent secretion of ,cypridina hilgendorfii will still give off much light if hydrogen containing only #j4d per cent4 of oxygen is bubbled through it1 i4e41 a partial oxygen pressure of #a_/bej atmosphere 7#c4jd mm4,hg74 ,however1 addition of a fresh emulsion of yeast cells to a glowing ,cypridina secretion is sufficient to rapidly extinguish the light1 because the yeast is capable of utilizing the last trace of oxygen in the mixture4 ,light only appears when1 by agitation1 we cause more air to dissolve4 ,the minimal concentration of oxygen for luminescence of ,cypridina lies somewhere between #c4jd mm4 and the amount which living yeast fails to extract from solution1 a concentration approaching zero4 ,it is probably nearer the latter figure4 ,as the oxygen pressure is increased from #j to about #g mm41 the intensity of the ,cypridina luminescence increases and at the latter figure the light is just as bright as if the solution were saturated with air 7#aeb mm4,o#b74 ,thus1 the luminescence requires only a low pressure of oxygen and the similarity to the saturation of haemoglobin with oxygen is obvious4 ,just as haemoglobin is nearly saturated with oxygen at low pressures and becomes bright red in color1 so the luminous material becomes saturated with oxygen at low pressures and glows intensely4 ,boyle also made many experiments to show that air was necessary for the life of animals and the germination of seeds and showed that repeatedly respired air was unfit for further breathing4 ,about the same time ,r4 ,hooke discovered the true meaning of respiratory movements and by forcing a blast of air continuously through the lungs with bellows1 was able to keep animals alive4 ,he concludes that as the bare ,motion of the ,lungs1 without fresh air1 contributes nothing to the life of the ,animal1 he being found to survive as well as when they were not moved as when they were2 so it was not the ,subsiding or ,movelessness of the ,lungs that was the immediate cause of death1 or the stopping of the circulation of the ,blood through the ,lungs1 but the ,want of a sufficient ,supply of fresh ,air4 ,the cause of death on collapse of the lungs could not be better stated to-day4 ,thus combustion1 respiration and luminescence of flesh or wood were early recognized as related phenomena4 ,although the gas sylvestre 7,,co#b7 of burning charcoal and fermentation of wine was known to van ,helmont 7#aegg-afdd7 and ,mayow 7#afdf-afgi7 in #afgd showed that spiritus nitroaerens 7oxygen7 was responsible for the life of animals and for combustion1 a century elapsed before the true significance of these gases became known4 ,in the meantime the phlogiston theory of combustion had been developed1 ,black 7#agbh-agii7 in #agee had rediscovered carbon dioxide 7fixed air7 in the expired air and ,priestley 7#agcc-ahjd7 and ,scheele 7#agdb-aghf7 had both rediscovered oxygen 7dephlogisticated air7 in #aggd4 ,about the same time ,lavoisier overthrew the phlogiston doctrine and showed that in the combustion of organic substances water and ,,co#b are formed4 ,later it was realized that this slow combustion did not take place in the lungs1 or in the blood1 but in the tissues cells themselves and respiration in the chemical sense has come to mean this universal slow combustion in the cells of the body rather than the breathing movements of the lungs themselves4 ,in anaerobic respiration1 ,,co#b is given off1 but no oxygen absorbed4 ,in aerobic respiration1 oxygen is absorbed and ,,co#b given off4 ,in addition we know of many substances which oxidize by taking up oxygen without giving off ,,co#b4 ,we have seen that oxygen must be absorbed for luminescence of animals and we may now inquire whether ,,co#b is given off and the relation between respiration and light production4 ,to determine if ,,co#b is given off during luminescence it is necessary to work with fairly pure luminous materials1 obtained from luminous organisms4 ,it is impossible to use the living organisms themselves as the ,,co#b continually respired becomes a very disturbing factor4 ,from ,cypridina1 a small crustacean1 two materials soluble in water may be prepared 7luciferin and luciferase71 which will give a brilliant luminescence on mixing4 ,it is possible to determine the ,h-ion concentration of the two solutions separately and of the mixture of the two after the luminescence has occurred4 ,if ,,co#b is produced during luminescence the ,h-ion concentration of the luminous solution should increase4 ,measurements made electrometrically with the hydrogen electrode have failed to demonstrate any increase in acidity4 ,the ,,ph of both solutions and of a mixture of the two is #i4jd4 ,this would indicate that ,,co#b is not produced4 ,as both luminous solutions contain proteins and the luminous substances themselves are probably proteins1 which have a high buffer value1 a method of this kind is none too sensitive4 ,however1 we can definitely state that not enough ,,co#b is produced to be detected and that this may be due to the buffer action of the luminous substances themselves4 ,after all1 unless luminescence is connected with respiration1 we should hardly expect ,,co#b to be produced4 ,another method of testing ,,co#b production is to measure the amount of heat produced during luminescence4 ,substances burned during respiration give off considerable heat1 one gram of glucose to ,,co#b and ,h#b,o1 as much as #djjj calories4 ,we have seen in ,chapter ,,iii that no infra-red radiation is produced in the light of the firefly4 ,this does not mean1 however1 that no heat is produced by the reaction which produces the luminescence4 ,a temperature change of a few thousandths or hundredths of a degree would evolve no measurable radiation4 ,coblentz 7#aiab7 first studied the problem of heat production in the firefly1 using a thermocouple as the measuring instrument4 ,he came to the conclusion that the temperature of the insect was slightly lower than the temperature of the air and that the luminous segments were slightly hotter than the non-luminous segments1 whereas a dead firefly is of the same temperature as its surroundings4 ,no definite increase or decrease in temperature could be established during the flash of the firefly4 ,however1 further work on the firefly is much to be desired4 ,the use of a living animal for such measurements introduces a possible source of error in that any contraction of the muscles of the animal will produce heat which may add to an increase or mask a decrease of temperature during luminescence4 ,utilization of extracts of luminous animals containing the luciferin and luciferase mentioned above avoids the complications due to muscular contraction4 ,by bringing the solutions of luciferin and luciferase to the same temperature and then mixing them one can measure any increase or decrease of temperature which occurs during the luminescence which results from mixing4 ,we can thus gain some idea of the heat of oxidation of luciferin4 ,as a determination of heat production is of considerable interest the method will be given in some detail4 ,although the experiment sounds very simple1 it is actually somewhat difficult to carry out4 ,the attainment of temperature equilibrium between two solutions is very slow when one wishes to obtain them to within #j4jja deg4 ,c4 of the same temperature4 ,after many attempts1 the following arrangement of apparatus 7,fig4 #cc7 was found most satisfactory4 ,about #aj c4c4 luciferin solution was placed in the inner tube 7,d7 of a special non-silvered thermos bottle 7,a74 ,about #a c4c4 of luciferase solution was placed in a very thin-walled glass tube 7,e7 which was immersed in the luciferin solution and connected with a small motor so that it could be slowly but constantly rotated1 thus stirring the solutions4 ,thermocouples 7,l and ,m7 of advance 74#jjh in7--copper 7,no4 #cj1 ,b and ,s1 enamel insulated7 wire were paraffined and placed in each tube and the copper wires connected through a copper double throw switch 7,c7 with a ,leeds and ,northrup d',arsonval wall galvanometer 7,no4 #cdfcg1 silver strip suspension7 of #ce ohms resistance and #caj megohms sensitivity4 ,the constant temperature junctions 7,n7 were placed in a large ,dewar flask 7,b7 filled with water at approximately the same temperature as the luciferin solution4 ,one mm4 galvanometer scale division represented #j4jjc deg4 ,c4 and the division readings could be estimated to tenths4 ,by means of a glass rod 7,f7 placed in the tube containing luciferase solution1 this tube could be broken and the luciferase and luciferin solution mixed4 ,illustration3 ,,fig4 #cc4--;,apparatus for determining heat production during luminescence of luciferin4 ,a1 special thermos tube4 ,b1 ,dewar flask for constant temperature junctions4 ,c1 double throw switch4 ,d1 tube containing luciferin solution4 ,e1 tube containing luciferase solution4 ,f1 glass rod for breaking ,e4 ,g1 rubber stopper with groove1 ,k1 for pulley cord4 ,h1 cork closing thermos tube4 ,j1 brass sleeve in ,h allowing rotation of ,e4 ,l1 thermojunction in luciferase solution4 ,m1 thermojunction in luciferin solution4 ,n1 constant temperature junctions4 ,illustration3 ,,fig4 #cd4--;,curve showing temperature change when two tubes containing water at the same temperature are mixed4 #j4a galvanometer scale division #j4jjc deg4 ,c4 ,dots represent readings of thermocouple in tube ,d2 crosses readings of thermocouple in tube ,e4 ,it was found that even after the luciferase and luciferin solutions came to the same temperature within the thermos bottle1 this was not necessarily the same as that of the room and a slow rise or fall occurred as indicated by a slow drift of the galvanometer coil4 ,readings of each thermocouple on the galvanometer scale were therefore taken at one-minute intervals for some time before and after mixing the luciferin and luciferase solutions and plotted as curves4 ,control experiments were also carried out in exactly the same manner as the luciferin-luciferase experiments1 but water was placed in the two tubes instead of luciferin and luciferase4 ,figs4 #cd and #ce give typical experiments with water and with luminescent solutions1 respectively4 ,illustration3 ,,fig4 #ce4--;,curve showing temperature change when luciferin and luciferase solutions at the same temperature are mixed4 #j4a galvanometer scale division #j4jjc deg4 ,c4 ,dots represent readings of thermocouple in luciferin solution2 crosses1 readings of thermocouple in luciferase solution4 ,with both control 7water7 and luciferin experiments there was a slight rise in temperature on mixing the liquids in the two tubes4 ,the average rise of five control 7water7 experiments was 4#jjed deg4 ,c4 and the average rise of five luciferin experiments was 4#jjdh deg4 ,c4 ,the average rise in temperature is no doubt due to heat from friction in mixing of the liquids and breaking of the glass tube4 ,the difference in the average rise of control and of luciferin experiments is so small 74#jjjf deg4 ,c47 as to have little significance4 ,we may therefore conclude that if any temperature change occurs during the luminescent reaction it is certainly less than #j4jja deg4 ,c4 and probably less than #j4jjje deg4 ,c41 too small to be measured by this method4 ,to prepare the luciferin solution1 two grams of dried ,cypridina were dissolved in #bj c4c4 hot water and #aj c4c4 of this #aj per cent4 solution was used in the thermos bottle in the above experiments4 ,if we assume that #a per cent4 of the dried ,cypridina is luciferin1 #j4ja gram of luciferin on oxidation was not able to raise the temperature of the #aj c4c4 7in reality #aa c4c41 since #a c4c4 luciferase solution was mixed with the #aj c4c4 luciferin solution7 4#jja deg4 ,c4 ,this means that #a gram luciferin liberates at least less than #aj calories during the luminescence accompanying oxidation4 ,since #a gram glucose liberates #djjj calories on complete oxidation to ,,co#b and ,h#b,o1 it will be seen that the oxidation of luciferin is a very different type of reaction from the oxidation of glucose4 ,as we shall see1 it is probably similar to the oxidation of reduced haemoglobin or the oxidation of leuco methylene-blue to methylene blue4 ,according to ,barcroft and ,hill 7#aiaj71 #a4he calories are produced per gram of haemoglobin oxidized4 ,i have been unable to find figures for the heat exchange during oxidation of leuco-dyes1 but it is no doubt also small4 ,since luciferin evolves no measurable amount of heat on oxidation1 we have very good evidence in support of that obtained by electrometric measurements of ,h-ion concentration1 that no carbon dioxide is produced during luminescence of luminous animals4 ,in most animal cells it is perfectly clear that luminescence does not accompany respiration1 since respiration is a continuous process1 whereas light is only produced on stimulation4 ,it is true that on stimulation respiration is accelerated1 and we might suppose that luminescence is an accompaniment of accelerated respiratory oxidations2 but this is not the case1 for in luminous animals a rise in temperature of ten degrees centigrade will accelerate the respiratory oxidations #bej per cent4 without necessarily causing the production of light4 ,in fungi and bacteria1 on the other hand1 which continually emit light1 it is quite natural to suppose that the light is an accompaniment of respiration1 just as we know the heat of these forms to be4 ,this view was accepted by such of the earlier workers as ,fabre in #ahee1 who found that luminous portions of a mushroom1 ,agaricus olearius1 gave off more ,,co#b 7#d4da c4c4 ,,co#b per gram in #cf hours at #ab deg4 ,c47 than non-luminous portions 7#b4hh c4c4 ,,co#b per gram in #cf hours at #ab deg4 ,c474 ,this experiment has never been repeated and there are many reasons besides luminescence why one piece of fungus might have a more rapid respiratory rate than another piece4 ,it is not true that rapidly respiring plant tissues1 such as germinating seeds or the spadix of ,araceae1 are luminous1 although they produce considerable heat4 ,on the other hand1 it is very easy to prove that luminescence1 even in bacteria1 is not connected with respiration4 ,thus1 ,beijerinck 7#ahhi c7 found that of several species of luminous bacteria studied by him1 one1 ,bacterium phosphorescens1 was a facultative anaerobe and would grow1 i4e41 multiply1 but not luminesce in the absence of oxygen4 ,some forms1 ordinarily producing light1 will grow1 but fail to luminesce at high temperatures4 ,beijerinck 7#aiae7 has recently found that these individuals may1 by continued cultivation at high temperatures1 form non-luminous strains which fail to luminesce when again brought into lower temperatures1 favorable for luminescence4 ,these non-luminous mutants occasionally give rise to atavistic brilliantly luminous forms4 ,beijerinck also finds that after exposure of ,photobacter splendidum to ultra-violet or strong sunlight1 radium or mesothorium rays1 luminescence continues but no growth occurs4 ,there is thus ample evidence that growth and respiration are properties quite distinct and separable from luminescence4 ,indeed1 respiration increases continuously up to a relatively high maximum whereas luminescence falls off rapidly above a relatively low optimum4 ,mc,kenney 7#aijb7 found also that ,bacillus phosphorescens could grow rapidly in #j4e per cent4 ether without producing light4 ,luminescence has been compared in bacteria to pigment formation1 as rather definite cultural conditions are necessary for realization of both chromogenic and photogenic function4 ,some pigment-formers1 as ,bacillus pyocyaneus1 which produces a water-soluble green pigment1 remain colorless under anaerobic conditions4 ,a colorless chromogen is formed1 which oxidizes to the green pigment in the air4 ,if this colorless chromogen produced light during its oxidation as well as green pigment1 we would have a case of both chromogenic and photogenic function combined in one species of bacterium4 ,luminescence involves something more than respiration1 an oxidation of a very definite and particular kind4 ,since ,spallanzani's observation that the luminous material of medusae could be dried1 and upon moistening would again give light1 many confirmatory observations have been made on other forms4 ,pyrosoma1 ,pholas1 ,phyllirrhoe1 fireflies1 ,pyrophorus1 copepods1 ostracods1 pennatulids1 fungi1 and bacteria can all be dessicated and the photogenic material preserved for a greater or less time4 ,in a dessicator filled with ,ca,cl#b1 dried luminous bacteria lose1 after a few months1 their power to give light on being moistened4 ,on the other hand1 ostracods and copepods will still luminesce after years of dessication4 ,the luminous material in the latter case appears capable of indefinite preservation1 but it is possible that the quick loss of photogenic power with dried luminous bacteria is merely an indication that they contain very little photogenic substance and that the dried ostracods would also in time lose their power to luminesce4 ,it is certainly a fact that the amount of luminous material in a single gland cell of an ostracod is vastly greater than that in the same mass of bacterial colony4 ,when the dried powdered luminous material of an ostracod is sprinkled over the surface of water1 it goes into solution and leaves luminous diffusion and convection trails plainly visible in the water4 ,many luminous marine forms give off a phosphorescent slime when they are handled1 which adheres to the fingers4 ,it is not surprising that this luminous matter should have early received a name4 ,in #ahgb1 ,phipson called it noctilucin and described some of its properties4 ,he regarded the luminous matter which can be scraped from dead fish 7luminous bacteria7 and the mucous secretion of ,scolopendra electrica or the luminous matter of the glowworm to be this material1 noctilucin1 which1 in moist condition1 takes up oxygen and gives off ,,co#b and when dry appears like mucin4 ,phipson says that it forms an oily layer over the seas in summer 7he probably refers to masses of dinoflagellates71 is liquid at ordinary temperatures and less dense than water1 smells a little like caprylic acid1 is insoluble in water but miscible with it1 insoluble in alcohol and ether1 dissolves with decomposition in mineral acids and alkalies and contains no phosphorus4 ,we can see from this description that the word noctilucin does not indicate a chemical individual1 but it is the earliest attempt to definitely designate the luminous substance4 ,the idea of a definite substance oxidizing and causing the light has been upheld by a number of investigators1 and many years later ,molisch called this substance the photogen4 ,he contrasts the photogen theory with certain other views of light production1 which may be spoken of as vital theories1 notably those of ,pflueger 7#ahge71 who looked upon luminescence as a sign of intense respiration1 and of ,beijerinck 7#aiae71 who regarded the light as an accompaniment of the formation of living matter from peptone4 ,fortunately biological science has advanced beyond the stage where a living process can be explained by calling it a vital process1 and we must fall back upon the idea of a photogen oxidizing with light production4 ,indeed1 it is now possible to go much further than this and describe the properties of the photogen1 but we must not lose sight of the fact that it was recognized very early in the history of ,bioluminescence1 that water1 oxygen1 and a photogenic substance were necessary for light production4 ,a very great advance in our knowledge of the chemistry of the problem was made by ,dubois in #ahhe4 ,he showed that if one dips the luminous organ of ,pyrophorus in hot water1 the light disappears and will not return again4 ,also if one grinds up a luminous organ the mass will glow for some time but the light soon disappears4 ,if one brings the previously heated organ in contact with the unheated triturated organ it will again give off light4 ,later1 ,dubois showed that the same experiment could be performed with the luminous tissues of ,pholas dactylus4 ,a hot-water extract of the luminous tissue1 and a cold-water extract of the luminous tissue1 allowed to stand until the light disappears1 will again produce light if mixed together4 ,dubois 7#ahhg b7 advanced the theory that in the hot-water extract there is a substance1 luciferin1 not destroyed by heating1 which oxidizes with light production in the presence of an enzyme1 luciferase1 which is destroyed on heating4 ,the luciferase is present together with luciferin in the cold-water extract1 but the luciferin is soon oxidized and luciferase alone remains4 ,mixing a solution of luciferin and luciferase always results in light production until the luciferin is again oxidized4 ,similar substances have been found by me in the ,american fireflies1 ,photinus and ,photuris1 the ,japanese firefly1 ,luciola1 and in the ostracod crustacean1 ,cypridina hilgendorfii4 ,crozier#f reports that they exist also in ,ptychodera1 a balanoglossid4 ,i have been unable to demonstrate their existence in luminous bacteria2 in the annelid1 ,chaetopterus2 the pennatulids1 ,cavernularia and ,pennatula2 the squid1 ,watasenia2 and the fish1 ,monocentris japonica4 ,e4 ,b4 ,harvey 7#aiag7 could not demonstrate them in ,noctiluca4 ,there are several reasons why the existence of such bodies might be difficult to demonstrate1 but these reasons cannot be considered here4 ,we thus see that the photogen is in reality of dual nature1 that two substances are necessary for light production and that they may be very readily separated because of difference in resistance to heating4 ,in this respect ,bioluminescence is similar to some other biological processes1 notably to certain immune reactions and to certain enzyme actions4 #f ,private communication4 ,thus1 for the haemolysis of foreign red blood corpuscles1 a specific immune body 7amboceptor or substance sensibilatrice7 not destroyed by moderate heating1 and a thermolabile complement 7alexin7 are necessary4 ,for the alcoholic fermentation of glucose by the zymase of yeast juice two substances are also necessary4 ,the zymase is made up of a heat resistant1 dialyzing component1 the co-enzyme1 and a non-dialyzing substance1 destroyed on boiling1 the enzyme proper4 ,both must be present for alcoholic fermentation of glucose to proceed and the two may be separated by dialysis or by their difference in resistance to heating4 ,several other characteristics of living cells are known to depend on the joint action of two substances1 one thermolabile1 the other thermostable4 ,the reducing action of tissues1 according to ,bach1 requires a reducing enzyme proper or perhydridase and some easily oxidizable substance1 such as an aldehyde4 ,the aldehyde has been spoken of as the co-enzyme4 ,because of the necessity of thermostable and thermolabile substances for light production in luminous animals and because ,i was unable to oxidize the thermostable material of ,cypridina with such oxidizing agents as ,k,mn,o#d1 ,h#b,o#b1 blood and ,h#b,o#b1 ,ba,o#b1 etc41 ,i called the heat resistant substance of ,cypridina1 photophelein 7from phos1 light and opheleo1 to assist71 comparable to co-zymase1 and the heat sensitive substance of ,cypridina1 photogenin 7from phos1 light and gennao1 to produce71 comparable to the zymase proper of yeast4 ,in mode of preparation and properties1 the photophelein of ,cypridina was also comparable to the luciferin of ,pholas and the photogenin of ,cypridina to the luciferase of ,pholas4 ,i also regarded photogenin as the source of the light 7hence the name71 because a solution of ,cypridina photogenin 7,pholas luciferase7 will give light on mixing with crystals of salt and other substances which could not possibly be oxidized4 ,i later found1 however1 that this result was due to the fact that the photogenin solution contained some of the thermostable substance 7luciferin7 bound 7combined or adsorbed71 and that this was freed by the salt crystals and oxidized with light production4 ,i have consequently abandoned the view that the system of substances concerned in light production is similar to the zymase--co-zymase system of yeast--and have adopted ,dubois' term1 luciferase 7photogenin7 for the thermolabile material1 and luciferin 7photophelein7 for the thermostable material4 ,the luciferin of ,cypridina differs from that of ,pholas in that it will not oxidize with light production with any oxidizing agents that ,i have tried1 and will give no light with luciferase from ,pholas4 ,it does1 however1 oxidize spontaneously in solution1 although no light accompanies this oxidation4 ,i believe that for accuracy and definiteness we must designate the luciferins and luciferases from different animals by prefixing the generic name of the animal and speak of ,pholas luciferin1 ,cypridina luciferase1 ,pyrophorus luciferase1 etc4 ,in extracts of many non-luminous animals ,dubois has found oxidizing agents which can oxidize ,pholas luciferin with light production and ,i have confirmed this for ,pholas1 but ,i have not found any such substances in non-luminous animals which will oxidize ,cypridina luciferin with light production4 ,i have found in extracts of non-luminous animals substances which will liberate the bound luciferin in a concentrated ,cypridina luciferase solution4 ,the luciferin can then be oxidized by the luciferase and light appears4 ,their effect is similar to that of salt crystals and ,i suggest that they be called photopheleins1 substances that assist in the luciferin-luciferase reaction by liberating bound luciferin4 ,one of the best ways of freeing a solution of luciferase from bound luciferin is to shake with chloroform4 ,we can then do away with the disturbing effects of bound luciferin4 ,it is obvious that luciferin must be formed from some precursor in the cell and following the usual biochemical terminology1 ,dubois has called it proluciferin or preluciferin1 and believes that it is converted into luciferin by an enzyme co-luciferase4 ,the experiments to prove the existence of proluciferin were first made by ,dubois on ,pholas in #aijg and have since been amplified 7#aiag a2 #aiah a and b74 ,in order to understand these experiments it must be borne in mind that ,dubois prepares luciferin from ,pholas in three ways3 7#a7 ,by precipitating the viscid luminous fluid from the siphons with #ie deg4 alcohol and dissolving the precipitate in water 7#aija;a1 #aijg74 7#b7 ,by extracting the luminous organs with #ij deg4 alcohol in a closed vessel for twelve hours and filtering 7#ahif74 7#c7 ,by heating the viscid luminous fluid to #gj deg4 ,c4 ,apparently ,pholas luciferin is sparingly soluble in alcohol as it can be obtained either in an alcoholic extract 7method #b7 or by precipitation with alcohol 7method #a74 ,proluciferin 7called preluciferine in a later paper1 #aiag a1 #aiah a71 is prepared by methods #a or #b except that fatigued siphons1 from which luciferin has been removed by washing1 are used 7#aijg1 #aiag a1 #aiah a74 ,preluciferin can also be obtained on boiling an extract of the luminous organ of ,pholas because luciferin 7at #gj deg471 luciferase 7at #fj deg47 and a co-luciferase are all destroyed below the boiling point 7#aiag a74 ,co-luciferase is prepared 7#a7 by heating a luciferase solution to #fe deg4 7#aiag a7 or 7#b7 by extracting with water portions of the siphon of ,pholas which have previously been macerated and well extracted with alcohol 7#aiah a74 ,long-continued treatment with alcohol apparently destroys the luciferase without affecting the co-luciferase4 ,on mixing a solution of preluciferin with one of co-luciferase and allowing them to stand for #h-aj hours1 luciferase is formed and can be recognized by the fact that it will give light with a crystal of ,k,mn,o#d4 ,preluciferine does not do this4 ,recently ,dubois 7#aiah a7 states that preluciferine is nothing but taurine and that taurine occurs in large quantities in ,pholas and is transformed into luciferine by the action of co-luciferase4 ,not only taurine1 but also ,byla's peptone1 egg lecithin1 and esculin can be converted into luciferine by co-luciferase1 and since esculin1 a glucoside1 is so transformed1 ,dubois believes this proves that co-luciferase belongs to the hydrolases4 ,indeed1 it proves too much4 ,luciferin must have an extraordinary chemical structure if it can be formed by hydrolysis of such diverse compounds as peptone1 lecithin1 esculin and taurine4 ,a glance at the structural formula of esculin and taurine is sufficient to emphasize the diverse nature of these two substances4 ,illustration3 ,taurine ,illustration3 ,esculin ,i believe that in these experiments ,dubois has been working with an oxidation product of luciferin1 what ,i have called oxyluciferin1 rather than a pro-substance4 ,the mode of preparation of ,pholas preluciferin and ,pholas co-luciferase is such as could be used in the preparation of ,cypridina oxyluciferin1 and it seems more logical to look for the presence of ,pholas oxyluciferin in one or both of ,dubois' extracts rather than believe that luciferin can be formed from both taurine and esculin4 ,when the co-luciferase solution stands with the preluciferin solution we would in reality have not the formation of luciferin from preluciferin1 but the formation of luciferin from oxyluciferin1 by some reducing agent in the mixture4 ,indeed1 in a very recent paper ,dubois 7#aiai c7 takes the view that his co-luciferase is a reducing enzyme which forms luciferin by reduction 7presumably from oxidized luciferin7 and no mention is made of preluciferin4 ,it is1 of course1 obvious that when luciferin oxidizes1 some oxidation products must be formed4 ,most observers have assumed the oxidation products of luciferin to be relatively simple and to represent a rather complete breaking down of the luciferin molecule4 ,carbon dioxide was mentioned by ,phipson 7#ahgb7 as being formed4 ,we have just seen that no carbon dioxide is formed during the oxidation of ,cypridina luciferin and there is evidence that no fundamental change at all occurs4 ,it is for this reason that ,i have called the oxidation product of luciferin oxyluciferin4#g ,as we shall later see1 the change luciferin oxyluciferin is to be compared to the oxidation of colorless dyes 7leuco-compounds7 to the colored dye4 ,the chemical properties of oxyluciferin are similar to those of luciferin and the oxyluciferin can be readily reduced to luciferin again4 #g ,it is unfortunate that ,dubois 7#aiah b7 has used the term oxyluciferine in a quite different sense from the present use4 ,he regards oxyluciferine as a substance still capable of giving light by autooxidation1 and represents the steps in luminescence as follows3 ,co-luciferase preluciferine luciferine4 ,luciferase luciferine oxyluciferine4 ,oxyluciferine oxygene lumiere4 ,i should represent them as follows3 ,luciferin oxygen oxyluciferin4 ,the reaction proceeds to right with light production only in presence of luciferase4 ,finally1 we have the fluorescent substance of ,pyrophorus and fireflies1 which ,dubois first called pyrophorin1 but later1 adopting ,mc,dermott's terminology1 speaks of as luciferesceine4 ,this ,dubois regards as a substance intensifying the light and modifying its color by changing invisible into visible rays4 ,as we have seen1 this theory1 while attractive1 will not stand the test of critical examination4 ,phipson's noctilucin1 while the first name for the photogen of luminous animals1 is too vague a substance1 chemically1 to warrant a retention of the term4 ,of the names1 luciferin1 luciferase1 preluciferin or proluciferin1 co-luciferase1 photogenin1 photophelein1 oxyluciferin1 luciferesceine1 ,i believe that only proluciferin1 luciferin1 oxyluciferin1 luciferase and photophelein stand for substances which are really significant for the theory of light production4 ,luciferin is the heat resistant1 dialyzable substance which takes up oxygen and oxidizes with light production in the presence of the heat sensitive1 non-dialyzing1 enzyme-like luciferase4 ,the luciferin must come from some precursor1 proluciferin1 but ,i have been unable to demonstrate the existence of this body in ,cypridina and know nothing definite of its properties4 ,the luciferin oxidizes to oxyluciferin which has the same chemical properties as the luciferin itself and may be reduced to luciferin again by reducing substances in luminous and other animals or by inorganic reducing agents4 ,photophelein is a name for substances in various animal or plant extracts which are capable of liberating luciferin from some bound condition in solutions containing luciferase4 ,under this term are included a number of unknown1 probably quite different substances1 some of which are thermostable and others thermolabile4 ,we have seen that ,bioluminescence is an oxyluminescence1 that the light is probably due to the oxidation of a compound1 luciferin1 in presence of air and water and that the oxidation is accelerated by an enzyme-like substance1 luciferase4 ,we also saw in ,chapter #b that light production is of fairly common occurrence during the oxidation of many organic compounds1 provided the oxidation is carried out in the proper way4 ,many of these organic compounds must be oxidized by relatively strong alkali or such strong oxidizing agents as would have a very deleterious action on living cells4 ,in #aiac1 ,ville and ,derrien1 in a short note to the ,french ,academy1 ,catalyse ,biochemique d'une ,oxydation ,luminescente1 show that lophin could be oxidized by vertebrate blood in the presence of ,h#b,o#b4 ,in the same year ,dubois 7#aiac7 found that esculin1 the glucoside from horse chestnut bark1 would also oxidize and luminesce in presence of blood and ,h#b,o#b4 ,in these cases the haemoglobin of the blood acts as a catalyst1 transferring oxygen from the ,h#b,o#b to esculin or lophin and is to be compared to luciferase1 except that luciferase does not require the presence of ,h#b,o#b4 ,as the haemoglobin does not lose this power on boiling1 whereas luciferase does1 the analogy is far from perfect4 ,many oxygen carriers are known1 however1 which may be destroyed on boiling their solutions1 namely1 the peroxidases of plant juices4 ,esculin will not luminesce with peroxidase and ,h#b,o#b1 but pyrogallol or gallic acid will4 ,if one mixes a test tube containing pyrogallol solution ,h#b,o#b with potato or turnip juice or almost any plant extract1 a yellowish luminescence appears4 ,the plant extract loses the power to cause such luminescence on boiling and the peroxidase will not dialyze4 ,it is1 of course1 comparable to luciferase and acts on the thermostable1 dialyzable pyrogallol-,h#b,o#b mixture1 which is comparable to luciferin4 ,curiously enough1 although many hydroxyphenol and amino-phenol compounds can be oxidized by peroxidase and ,h#b,o#b1 only pyrogallol and gallic acid will oxidize with light production4 ,many other oxidizers can take the place of the peroxidase4 ,a list of these is given on page #aea4 ,no other peroxide can take the place of ,h#b,o#b with peroxidases as oxidizers1 but a few can replace ,h#b,o#b with other oxidizers4 ,this is brought out in ,table #g4 ,,table #g ,peroxides ,giving ,light with ,pyrogallol and ,oxidizers ,key to column headings3 ,a3 ,oxidizer4 7,equal parts added to a mixture of ,m_/#ajj pyrogallol and the peroxide7 ,b3 ,h#b,o#b #c per cent4 ,c3 ,benzoyl hydrogen peroxide 7insoluble powder7 ,d3 ,ozonized turpentine 7one drop7 ,e3 ,na#b,o#b 7powder7 ,f3 ,ba,o#b 7powder7 ,g3 ,mn,o#b 7insoluble powder7 ,h3 ,pb,o#b 7insoluble powder7 ,i3 ,k persulfate ,m_/#aj ,j3 ,na perborate ,m_/#bj ,k3 ,k perchlorate ,m_/#aj ,l3 ,quinone 7insoluble crystals7 ---------------------------------------- ------------------------------------- ,a ,b,c,d ,e ,f ,g,h ,i ,j ,k,l --------------------------- -------------------------------------- ,turnip juice - - - - - - - - #a percent blood extract - - ,faint - - - - - - - flash ,m #bj ,k#d;,fe7,,cn7#f - - - - - - - - - - ,m #ajj ,k,mn,o#d - - - - - - ,faint,fair - - flashflash ,m #aj ,fe,cl#c - - ,m #ajj ,cr,o#c - - ,na hypobromite - - ,faint,faint - - ,fair ,fair - - flashflash flashflash ,ca hypochlorite - - - - - - ,faint,fair - - flash ,mn,o#b ,mn7,,oh7#c sol in peptone - - ,colloidal ,ag ---------------------------------------- -------------------------- ,our knowledge of the existence of such analogous1 purely organic chemical oxidations1 which proceed with light production1 greatly strengthens ,dubois' theory that the luciferin-luciferase reaction really represents a catalytic oxidation of similar nature4 ,as ,dubois 7#aiad a7 expresses it1 we are dealing in luminous organisms with #a deg4 une luminescence2 #b deg4 une chemiluminescence2 #c deg4 une oxyluminescence2 #d deg4 une zymoluminescence4 ,ou si l'on bien admettre que les zymases sont encore quelque chose de vivant1 une ,biozymooxyluminescence4 ,perhaps it is not really necessary to admit that the enzymes are living in order that we may adequately visualize the nature of the photogenic process4 ,in the next chapter the properties of the three principal substances1 luciferin1 oxyluciferin and luciferase1 will be studied more carefully4 ,,chapter ,,vi ,,the ,,chemistry ,,of ,,light ,,production1 ,,part ,,ii ,since ,radziszewski's experiments on the oxidation of oils in alcoholic solutions of alkali1 most of the early workers on ,bioluminescence tacitly assumed that the oxidizable material was fat or a fat-like substance4 ,support was given to this view by the occurrence in cells of granules or globules from which the light was seen to come4 ,we now know that these bodies are not fat droplets and that neither luciferin nor luciferase are soluble in such fat solvents as ether1 chloroform1 benzol or benzine4 ,phipson's description of the properties of noctilucin are too crude and inaccurate to be considered4 ,dubois did not study the chemical properties of luciferin and luciferase from ,pyrophorus1 the first form with which he worked1 except to point out that ,pyrophorus luciferase was destroyed on heating and was precipitated by alcohol while the ,pyrophorus luciferin was not so affected4 ,luciferin was found only in the luminous organ of ,pyrophorus1 not in the blood2 luciferase probably exists throughout the animal4#h #h ,private communication from ,r4 ,dubois4 ,,pholas ,,luciferin4--,in a series of papers since #ahhg ,dubois has studied the chemical properties of ,pholas luciferin and ,pholas luciferase4 ,he finds the luciferin to be destroyed above #gj deg4 ,c41 to dialyze slowly1 to oxidize with light production in the presence of ,pholas luciferase1 ,k,mn,o#d1 ,h#b,o#b1 haematine and ,h#b,o#b1 ,ba,o#b1 ,pb,o#b1 hypochlorites1 and the blood of various marine mollusks and crustacea4 ,it is insoluble in fat solvents but forms a colloidal solution in water from which it is precipitated unchanged by picric acid1 alcohol at #hb deg41 and 7,,nh#d7b,,so#d4 ,it is not precipitated by ,na,cl1 ,mg,s,o#d or acetic and carbonic acids1 except in presence of neutral salts4 ,it forms an insoluble alkali albumin with ,,nh#d,,oh4 ,dubois 7#ahhg a7 stated at one time that it could be crystallized and has spoken of it as belonging to several different classes of substances1 proteose1 nucleoprotein1 albumin4 ,most recently he describes luciferin as a natural albumin having acid properties4 ,it occurs only in luminous1 not in non-luminous animals1 and is found in all parts of the mantle1 especially the siphons4 ,it does not occur in non-luminous parts of the mollusk4 ,no photographs of luciferin crystals have ever been published4 ,,pholas ,,luciferase4--,pholas luciferase has all the properties of an enzyme1 is destroyed at #fj deg4 ,c41 is non-dialyzable1 insoluble in fat solvents1 but forms a colloidal solution in water4 ,it is not affected by #a per cent4 ,na,f but its activity is suspended in saturated salt solutions1 sugar or glycerine1 and it may be preserved in this way1 its activity returning on dilution4 ,it is digested by trypsin and slowly destroyed by the fat solvent anaesthetics1 such as chloroform4 ,for this reason ,dubois regards it as an oxidizing enzyme similar to the oxydones of ,batelli and ,stern4 ,because he found iron in an extract of ,pholas dialyzed for a long time against running water1 ,dubois considers that it is associated with iron1 and reports that it will oxidize the ordinary oxidase reagents1 such as pyrogallol1 gum guaiac1 a-naphthol and para-phenylene-diamine1 etc4 ,it remains to be proved1 however1 that luciferase and not the oxidizing systems such as occur in all cells are responsible for the coloration of these reagents4 ,dubois has found luciferases or substances capable of giving light with ,pholas luciferin in the blood of many non-luminous crustacea and mollusks 7in ,barnea candida1 ,solen1 ,cardium edulis1 ,ostraea and ,mytilus74 ,,cypridina ,,luciferin4--,despite the large amount that has been written on luminous animals1 ,dubois' work on ,pholas and my own on ,cypridina and the firefly are the only truly chemical studies that give us any idea of the nature of the photogenic substances in any luminous animal4 ,in many ways ,cypridina luciferin is similar to ,pholas luciferin1 but the two differ in a sufficient number of points to make certain that they are not identical substances4 ,as ,i have emphasized above1 we should speak not of luciferin and luciferase but of the luciferins and the luciferases4 ,the luciferins1 as the oxidizable substances1 must claim first attention4 ,they are more simple substances than the luciferases4 ,if we are to produce light artificially in the same way that animals do1 the luciferins must be synthesized4 ,the luciferin of ,pholas will luminesce with ,k,mn,o#d and other oxidizing agents1 and1 although ,i have not yet succeeded in oxidizing ,cypridina luciferin with oxidizing agents1 ,i have no doubt but that some inorganic catalyzer will be found to take the place of luciferase and accelerate oxidation of ,cypridina luciferin with light production4 ,the most remarkable peculiarity of ,cypridina luciferin is its stability4 ,in my first paper on ,cypridina ,i stated that luciferin was not destroyed by momentary boiling but would be destroyed if boiled four or five minutes2 also1 that it was unstable at room temperatures and would disappear from solution in the course of a day or so4 ,the reason for this is that luciferin oxidizes even in absence of luciferase and will then no longer give light with luciferase4 ,this spontaneous oxidation1 which occurs without light production1 can be prevented by keeping the luciferin in a hydrogen atmosphere or by the addition of acid4 ,under these conditions the luciferin can be boiled without destruction or preserved for months without deterioration4 ,the rapid disappearance of luciferin from neutral or alkaline solution on boiling in the air is entirely due to the more rapid oxidation at the boiling point4 ,as the oxidation product1 oxyluciferin1 can be readily reconverted into luciferin again1 we can not consider luciferin unstable in the sense that its molecule is actually destroyed as is the case when luciferase is boiled4 ,not only is luciferin stable on boiling but it will actually withstand boiling for #aj hours with #bj per cent4 ,h,cl 7by weight1 sp4 gr4 #a4a7 or with #d per cent4 ,h#b,,so#d4 ,after one day of boiling with #bj per cent4 ,h,cl the luciferin was completely destroyed and with #d per cent4 ,h#b,,so#d destruction was almost complete4 ,in these cases there was no question of a mere oxidation to oxyluciferin1 as no oxyluciferin could be demonstrated after boiling with such strong acids4 ,an actual destruction1 probably an hydrolysis of the luciferin molecule1 occurred4 ,we shall have occasion to refer to this again in considering the protein nature of luciferin4 ,it must be borne in mind that many proteins require four or five days' boiling with #bj per cent4 ,h,cl for complete hydrolysis to amino-acids4 ,luciferin forms a solution in water1 probably colloidal1 although the luciferin will dialyze through parchment or collodion membranes4 ,it is rather readily adsorbed by various finely divided materials such as bone black1 ,fe7,,oh7#c1 kaolin1 talc and ,ca,co#c4 ,it is not destroyed by any of the enzyme solutions which ,i have tried4 ,these include such as are widely divergent in action3 pepsin ,h,cl1 trypsin1 erepsin1 salivary and malt diastase1 yeast invertase1 urease1 rennin and the enzymes of dried spleen1 kidney and liver substances4 ,by extracting the dried ,cypridinas ground to a powder1 the solubility of luciferin in non-aqueous solvents could be easily studied1 and by adding such reagents as dilute acids1 alkalies1 neutral salts and the alkaloidal reagents to an aqueous solution of luciferin the general biochemical behavior of luciferin can be quite accurately stated4 ,for convenience the results of this study are given in ,table #h4 ,,table #h ,properties of ,photogenic ,substances from ,cypridina ,property ,luciferase ,luciferin ---------------------------------------- ------------------------------- ,salting out ,by saturation ,na,cl ,not precipitated ,not precipitated4 ,by half saturation ,do4 ,do4 ,mg,s,o#d ,by saturation ,mg,s,o#d,nearly completely ,partially precipitated precipitated4 ,by saturation ,mg,s,o#d 444 ,do4 acetic acid ,by half saturation 7,,nh#d7b,,so#d ,slightly precipitated ,not precipitated4 ,by saturation ,completely precipitated,nearly completely 7,,nh#d7b,,so#d precipitated4 ,by saturation 7,,nh#d7b,,so#d 444 ,nearly completely acetic acid precipitated4 ,solubility in ,methyl alcohol ,insoluble ,soluble4 ,ethyl alcohol ,do4 ,do4 #ij per cent4 ,do4 ,do4 #gj per cent4 ,do4 ,do4 #ej per cent4 ,slightly soluble ,do4 ,propyl alcohol ,insoluble ,do4 ,isobutyl alcohol ,do4 ,fairly soluble4 ,amyl alcohol ,do4 ,slightly soluble4 ,benzyl alcohol ,do4 ,soluble4 ,acetone ,do4 ,fairly soluble4 #ij per cent4 ,do4 ,soluble4 #gj per cent4 ,slightly soluble ,do4 #ej per cent4 ,fairly soluble ,do4 ,ethyl acetate ,insoluble ,do4 ,ethyl propionate ,do4 ,fairly soluble4 ,ethyl butyrate ,do4 ,do4 ,ethyl valerate ,do4 ,slightly soluble4 ,ethyl nitrate ,do4 ,very slightly soluble4 ,glycerine ,do4 ,soluble4 ,glycol ,do4 ,do4 ,ether ,do4 ,insoluble4 ,chloroform ,do4 ,do4 ,carbon disulfide ,do4 ,do4 ,carbon tetrachloride ,do4 ,do4 ,benzol ,do4 ,do4 ,toluol ,do4 ,do4 ,xylol ,do4 ,do4 ,petroleum ether ,do4 ,do4 ,anilin ,do4 ,do4 ,glacial acetic acid ,do4 ,fairly soluble4 ,alkaloidal ,reagents ,phosphotungstic acid ,completely precipitated,very nearly completely precipitated4 ,phosphotungstic and 444 ,very nearly completely acetic acids precipitated4 ,phosphotungstic acid 444 ,completely precipitated4 and ,h,cl ,tannic acid ,nearly completely ,nearly completely precipitated precipitated4 ,tannic and acetic 444 ,nearly completely acids precipitated4 ,tannic acid and ,h,cl 444 ,nearly completely precipitated4 ,picric acid ,nearly completely ,not precipitated4 precipitated ,picric and acetic acid 444 ,do4 ,picric acid and ,h,cl 444 ,do4 ,k#d;,fe7,,cn7#f and 444 acetic acid ,do4 ,heavy ,metal ,salts ,basic lead acetate ,completely precipitated,not completely precipitated4 ,neutral lead acetate ,nearly completely ,not completely precipitated4 precipitated4 ,neutral lead acetate 444 ,not precipitated4 and acetic acid ,mercuric chloride ,not precipitated ,not completely precipitated4 ,mercuric chloride and 444 ,almost completely acetic acid precipitated4 ,uranyl nitrate and 444 ,not completely acetic acid precipitated4 ,acids and ,alkalies ,na,o,h ,not precipitated ,not precipitated4 ,,nh#d,,oh ,do4 ,do4 ,acetic acid ,do4 ,do4 ,h#b;,,co#c ,do4 ,do4 ,trichloracetic acid ,do4 ,do4 ---------------------------------------- ------------------------------- ,because the luciferin is almost completely precipitated by saturation with 7,,nh#d7b,,so#d1 we may conclude that it occurs in water in the colloidal state4 ,this excludes it from belonging to one of the numerous groups of biochemical compounds occurring in true solution and places it among the known groups of colloidal substances1 the soaps1 proteins1 polysaccharides1 phospholipins1 galactolipins 7cerebrosides71 tannins or saponins4 ,it is not a polysaccharide because nearly completely precipitated by phosphotungstic acid1 nor a soap because not precipitated by calcium salts1 nor a phospho- or galactolipin because insoluble in benzine1 hot or cold4 ,it gives no tannin or saponin tests4 ,only the protein group remains1 and of the eighteen protein classes recognized by the ,american ,society of ,biochemists1 the general properties of luciferin indicate that it should be placed among the natural proteoses1 somewhere on the borderland between the proteoses and peptones4 ,the fact that luciferin will dialyze1 although almost completely salted out by 7,,nh#d7b,,so#d1 is strong evidence in favor of placing it in such a position4 ,on the other hand1 luciferin has two properties which to say the least are unusual for proteins4 ,i refer to its solubility in alcohols1 acetone1 esters1 etc41 and non-digestibility by trypsin or erepsin1 which have almost universal proteolytic power4 ,the best known class of proteins soluble in alcohol is the prolamines of plants1 but the prolamines are insoluble in water and in absolute alcohol4 ,zein1 the prolamine of corn1 is soluble in #ij per cent4 ethyl1 methyl1 and propyl alcohols1 in glycerol heated to #aej deg4 ,c41 and in glacial acetic acid4 ,recently ,osborne and ,wakeman 7#aiah7 have described a protein from milk having solubilities similar to those of gliadin1 the prolamine of wheat4 ,welker 7#aiab7 has described a substance1 obtained from ,witte's peptone1 giving the biuret1 ,millon1 and ,hopkins-,cole tests1 which is soluble in water and absolute alcohol but not in ether1 and it is possible that others of the peptones are soluble in absolute alcohol4 ,on the other hand1 some proteins in the absence of salts form colloidal solutions in strong alcohol from which they may be precipitated by an appropriate salt4 ,as the absolute alcohol extract of ,cypridinae was made from dry material containing the salts of sea water1 some salt was present1 but there is always the possibility of sol formation4 ,if we extract dried ,cypridinae1 which have previously been thoroughly extracted with benzine or ether1 with #hjj c4c4 of boiling absolute alcohol for an hour1 filter the alcohol extract through blotting paper and hardened filter paper1 quickly evaporate the filtrate to dryness on the water bath1 and dissolve the residue in a small quantity of water saturated with ,,co#b1i we obtain a yellow opalescent solution which gives a bright light with luciferase4 ,this solution contains some protein or protein derivatives as it gives a very faint ,millon reaction1 a good positive ninhydrin test1 reddish blue in color1 but no biuret reaction4 ,it precipitates with tannic and phosphotungstic acids but not with picric1 acetic1 trichloracetic1 or chromic acids4 ,the extract gives a faint ,molisch reaction for carbohydrates4 ,as the evidence points to the presence of some protein products in the absolute alcohol extract of ,cypridinae1 it is possible that this protein is luciferin4 ,it should be emphasized1 however1 that the ,millon reaction was very faint1 although the ninhydrin was quite marked and the biuret negative4 #i ,to make the solution slightly acid and prevent oxidation of the luciferin4 ,although luciferin is not digested by trypsin1 even after five days at #ch deg4 ,c41 it does hydrolyze with mineral acids after about #af hours' boiling4 ,some proteins1 the albuminoids and racemized proteins1 resist tryptic digestion but yield to acid hydrolysis4 ,we know also that some ,,nh-,,co linkages of proteins are broken down with great difficulty by trypsin as it is difficult to obtain a tryptic digest of protein which does not give the biuret reaction1 and the work of ,fischer and ,abderhalden has shown that certain artificial polypeptides are not digested by pure activated pancreatic juice4 ,we have1 then1 three possibilities3 ,luciferin is 7#a7 either a natural proteose not attacked by trypsin1 or 7#b7 if attacked by trypsin its decomposition products 7presumably amino-acids7 still contain the group oxidizable with light production1 or 7#c7 it is not protein at all4 ,i have been unable to oxidize with light production various mixtures of amino-acids 7from tryptic digestion of beef and casein1 or the acid hydrolysis products of luciferin itself7 by means of luciferase1 and consequently am led to believe that ,cypridina luciferin is either a new natural proteose1 soluble in absolute alcohol and not digested by trypsin or that it belongs to some other group than the proteins4 ,the absence of a biuret reaction would point in that direction and the question must await further study4 ,cypridina luciferin is found in the luminous gland of the animal and possibly in parts non-luminous as well as in the luminous organ4 ,this is true of the luciferin from fireflies which is found throughout the body of ,luciola1 ,photuris and ,photinus4 ,,cypridina ,,luciferase4--,luciferase1 on the other hand1 has all the properties of a complex protein4 ,it will not dialyze through collodion or parchment membranes1 is soluble only in aqueous solvents1 and hence precipitated by alcohol and acetone1 digested by proteolytic enzymes1 readily changed by contact with dilute acid and alkali and irreversibly coagulated on boiling4 ,it is completely salted out of solution by saturation with 7,,nh#d7b,,so#d and nearly completely precipitated by the alkaloidal reagents4 ,its other properties are given in ,table #h4 ,taken together1 they point to the group of albumins as the class of proteins with which luciferase most closely agrees4 ,if luciferase is not a protein it is so closely bound up with protein that it cannot be separated4 ,this is characteristic of many enzymes and luciferase is also an enzyme4 ,we can determine this by finding out whether luciferase will accelerate the oxidation of a large amount of luciferin1 for such is the test of a catalytic substance4 ,if we take #a c4c4 of a dilute solution of luciferase 7#a ,cypridina to #ej c4c4 water7 and add to it successive #a c4c4 portions of concentrated luciferin 7#a ,cypridina to #b c4c4 solution7 as soon as the light from the preceding addition has disappeared1 after four #a c4c4 additions1 no more light is produced4 ,the luciferase is therefore used up and cannot oxidize more than a certain quantity of luciferin4 ,in this experiment1 however1 we added a concentration of luciferin from one ,cypridina #ajj times that of the luciferase from one ,cypridina1 i4e41 four additions each #be times as concentrated4 ,we have1 of course1 no way of telling what the absolute amount 7in milligrams7 of luciferin or luciferase is in a single ,cypridina1 but we do know that the luciferase from one ,cypridina cannot oxidize luciferin from more than #ajj ,cypridinas4 ,if the ratio of luciferin to luciferase in a single animal is #ajj3a1 it would mean that luciferase could oxidize #aj1jjj times its weight of luciferin4 ,a large excess of luciferin but not an indefinite quantity can be oxidized by luciferase1 and ,i believe this is sufficient justification for considering luciferase an enzyme1 although it is not an ideal example of an organic catalyzer4 ,quite a number of enzymes are known to be diminished during the course of the reaction they accelerate or to be poisoned by their reaction products4 ,enzyme reactions inhibited by the formation of reaction products again proceed if these are removed or diluted4 ,however1 light does not again appear in a mixture of weak luciferase with excess of luciferin upon dilution with water1 so that the luciferase cannot have been merely inhibited by some reaction product but must have been actually used up during the reaction4 ,it should be noted in passing that the peroxidases1 ordinarily spoken of as oxidizing enzymes1 are used up in the reaction and can only oxidize limited amounts of oxidizable substances1 a quantity almost in proportion to the concentration of peroxidase present4 ,whether luciferase is an oxidizing enzyme made up of an albumin associated with some heavy metal as iron1 copper or manganese is uncertain4 ,from analyses of whole ,cypridina1 kindly made for me by ,prof4 ,a4 ,h4 ,phillips of ,princeton ,university1 all three of these metals1 which we know to be associated with biological oxidations1 are present1 and it is quite possible that one of them is concerned with the oxidation of luciferin4 ,although ,i have tested a great many oxidizers1 organic and inorganic1 and a large number of oxidizing enzymes from blood and tissue extracts of animals rich in iron1 copper and manganese1 ,i have found no material which is capable of taking the place of ,cypridina luciferase4 ,peroxidases or oxidases of plants1 haemoglobin1 haemocyanin1 extracts of mussels1 manganese containing blood of various marine crustacea and mollusks will give no light on mixing with luciferin4 ,such active oxidizers as ,k,mn,o#d1 ,h#b,o#b1 ,ba,o#b1 and many others1 will not oxidize ,cypridina luciferin with light production1 although they can oxidize ,pholas luciferin with light production4 ,the action of ,cypridina luciferase is very highly specific4 ,it is found only in the luminous organ of ,cypridina hilgendorfii1 not in non-luminous parts and not in a non-luminous species of ,cypridina closely related to hilgendorfii4 ,luciferins and luciferases from closely allied luminous forms will mutually interact to produce light1 but no light appears if these substances come from distantly related forms4 ,thus firefly 7,photuris7 luciferin will give light with ,pyrophorus luciferase and vice versa1 but ,cypridina luciferin will give no light with firefly 7,luciola7 luciferase or vice versa1 nor with ,pholas luciferase or vice versa4 ,the faint luminescences sometimes observed on mixing firefly or ,cypridina luciferase with boiled extracts of non-luminous forms1 or of distantly related luminous forms1 are probably caused by photophelein in the boiled extract4 ,like the plant peroxidases1 ,cypridina luciferase is not readily affected by the action of chloroform1 toluol1 etc4 ,unlike the plant peroxidases1 it will not oxidize 7i4e41 produce coloration7 in either presence or absence of ,h#b,o#b1 any of the hydroxyphenol or aminophenol compounds1 such as pyrogallol1 a-naphthol1 para-diamino-benzine1 gum guaiac1 etc41 commonly used as peroxidase reagents4 ,neither will luciferase produce light with any substances1 such as oils1 lophin1 pyrogallol1 gallic acid1 esculin1 etc41 which we know to be capable of oxidation with light production by other means4 ,the luciferases are very highly specific and act only upon the luciferins of the same or closely related species4 ,they must be placed by themselves in a new class of oxidizing enzymes4 ,according to ,dubois1 ,pholas luciferase is rather readily destroyed by chloroform and my own observations indicate that this is true also of firefly luciferase1 so that a certain amount of variation exists in the group of luciferases4 ,none of the luminescent animals which ,i have studied are at all affected by cyanides4 ,the luminescence continues in extracts of ,cypridina1 firefly1 and ,cavernularia1 or in ,noctiluca and luminous bacteria after addition of small or high 7m_/#dj7 concentrations of ,,kcn4 ,in this respect the luciferases are very different from many types of oxidizing enzymes which are inhibited by exceedingly weak concentrations of cyanide4 ,it should be borne in mind1 however1 that while ,,kcn inhibits catalase and the catalytic decomposition of ,h#b,o#b by ,pt or ,ag1 it does not affect the catalytic decomposition of ,h#b,o#b by thallium4 ,,oxyluciferin4--,when luciferin is oxidized it must be converted into some substance or substances and ,i believe this change involves no fundamental destruction of the luciferin molecule as it is a reversible process4 ,i shall speak of the principal 7if not the only7 product formed as oxyluciferin4 ,if we assume that the oxidation of luciferin changes the molecule but slightly1 we at once think of comparing the change luciferin oxyluciferin with the change reduced haemoglobin oxyhaemoglobin4 ,the condition is1 however1 not so simple as this1 for oxyhaemoglobin will again give up its oxygen providing the partial pressure of oxygen is made sufficiently low1 whereas oxyluciferin will not do this1 at least in the dark4 ,we can not reduce oxyluciferin solution by exhausting the oxygen with an air-pump4 ,there is another oxidation-reduction system which can also be easily reversed1 but not by merely removing the oxygen from the solution--that is1 the reduction of a dye such as methylene blue to its leuco-base4 ,i believe the change which occurs when luciferin is oxidized is similar to that which occurs when the leuco-base of methylene blue or sodium indigo-sulphonate is oxidized to the blue dye4 ,oxidation of leuco-dye bases occurs spontaneously in presence of oxygen and appears to consist in the removal of hydrogen from the leuco-base with formation of water4 ,reduction of these dyes may be effected in the same ways that oxyluciferin can be reduced4 ,in the case of methylene blue1 reduction consists in the addition of two hydrogen atoms4 ,whether a similar change occurs when oxyluciferin is reduced or whether oxygen is actually added as in formation of haemoglobin cannot be definitely stated at present4 ,we may write equations representing these possibilities as follows3 ,c#af;,h#bj,n#c,s,cl7leuco-methylene blue7 ,o ,c#af;,h#ah,n#c,s,cl 7methylene blue7 ,h#b,o ,haemoglobin ,o oxyhaemoglobin4 ,let us now turn to the methods which may be used in reduction of oxyluciferin4 ,we may then endeavor to write an equation which will represent the fundamental changes in the luminescence reaction4 ,my attempts to reduce the oxidation product of luciferin started from the observation that if one places a clear solution of luciferase in a tall test tube1 although it may give off no light at first when shaken1 after standing a day or so a very bright light would appear on shaking4 ,this was especially true when the luciferase had become turbid and ill-smelling from the growth of bacteria4 ,thinking that the bacteria produced a substance which could be oxidized by the luciferase1 ,i tried growing bacteria and also yeast on appropriate culture media1 and after some days of growth mixing the culture media containing the products of bacterial or yeast growth with luciferase1 expecting to obtain light2 but no light appeared4 ,however1 if a little crude luciferase solution was added to the bacterial or yeast cultures and then allowed to stand for some hours1 light appeared whenever they were shaken4 ,indeed such cultures behaved much as a suspension of luminous bacteria which has used up all the oxygen in the culture fluid and will only luminesce when1 by shaking1 more oxygen dissolves in the culture medium4 ,realizing that in bacterial cultures in test tubes1 anaerobic conditions soon appear1 and also the strong reducing action of bacteria upon many substances 7for instance1 nitrates or methylene blue7 under anaerobic conditions1 it struck me that the bacteria might be reducing the oxidation product of luciferin to luciferin again4 ,we must remember that since crude luciferase solution is a cold-water extract of a luminous animal allowed to stand until all the luciferin has been oxidized1 it must contain oxyluciferin as well as luciferase and will give light if the oxyluciferin is again reduced and oxygen admitted4 ,this appears to be the correct explanation of the above experiments4 ,oxyluciferin may also be readily reduced by the use of the blood of the horse-shoe crab 7,limulus7 allowed to stand until bacteria develop4 ,this experiment is of special interest because the blood contains haemocyanin1 which is colorless in the reduced condition and blue in the oxy-condition4 ,the color change thus serves as an indicator of the oxygen concentration in the blood4 ,a sample of foul-smelling ,limulus blood full of bacteria will become colorless on standing in a test tube for #aj to #ae minutes1 but the blue color quickly returns if shaken with air4 ,such a blood has the power of reducing oxyluciferin through the activity of the bacteria which it contains4 ,fresh blood has very little if any reducing action4 ,not only bacteria but also tissue extracts have a strong reducing action in absence of oxygen4 ,thus1 muscle tissue stained in methylene blue will very quickly decolorize 7reduce7 the methylene blue if oxygen 7air7 is kept away1 but the blue color immediately returns if air is admitted4 ,oxyluciferin 7i4e41 a solution of luciferin which has been completely oxidized by boiling or standing in air until it no longer gives light with luciferase7 if mixed with a suspension of ground frog's muscle and kept in a well-filled and stoppered test tube for some hours1 is reduced to luciferin and gives a bright light if now poured into luciferase solution4 ,frog muscle suspension alone1 or oxyluciferin alone1 give no light with luciferase1 nor will a mixture of frog muscle suspension and oxyluciferin1 if shaken with air for several hours4 ,only if this last mixture be kept under anaerobic conditions is the oxyluciferin reduced4 ,the reducing action of tissues is said to be due to a reducing enzyme 7reducase or reductase71 itself composed of a perhydridase and some easily oxidized body such as an aldehyde4 ,in the presence of the perhydridase the oxygen of water oxidizes the aldehyde and the hydrogen set free reduces any easily reducible substance which may be present4 ,there is a perhydridase in fresh milk1 spoken of as ,schardinger's enzyme1 which is destroyed by boiling4 ,if some aldehyde is added1 fresh milk will reduce methylene blue to its leuco-base or nitrates to nitrites1 upon standing a short time4 ,if shaken with air the blue color returns4 ,there is no reduction unless an aldehyde is added or unless some boiled extract of a tissue such as liver is added4 ,the boiled-liver extract has no reducing action of its own1 but supplies a substance similar to the aldehyde which has been spoken of as co-enzyme4 ,the aldehyde is oxidized to its corresponding acid4 ,milk will reduce methylene blue without aldehyde if bacteria are present in large numbers4 ,there is no reduction if the milk1 methylene blue1 and aldehyde are agitated with air4 ,the temperature optimum is rather high1 #fj deg4 to #gj deg4 ,c4 ,i find that milk is a favorable and convenient medium for the reduction of oxyluciferin and that it acts without the addition of an aldehyde or the presence of bacteria4 ,there is probably a substance acting as the aldehyde in the luciferase-oxyluciferin solution4 ,no light appears if milk is added to a luciferase-oxyluciferin solution1 but if the mixture is allowed to stand in absence of oxygen light will appear when air is admitted4 ,the air can be conveniently kept out by filling small test tubes completely with the solution and closing them with rubber stoppers4 ,as almost all animal tissues contain reductases it is not surprising to find that a freshly prepared and filtered extract of ,cypridina containing oxyluciferin and luciferase1 which gives no light on shaking1 will1 on standing in a stoppered tube for #bd hours at room temperature in the dark give light when air is admitted4 ,while this may be due to the development of bacteria with a reducing action1 it does not seem likely1 as under the same conditions methylene blue is not reduced in #bd hours1 and there is no turbidity or smell of decomposition in the tube4 ,in #dh hours bacteria appear and methylene blue is also reduced4 ,if we add chloroform1 toluol or thymol to the tubes of ,cypridina extract to prevent the growth of bacteria1 and allow them to stand #dh hours1 upon admitting air the tube with chloroform gives no light but the tubes with toluol and thymol do give light1 although it is not so bright as if they were absent4 ,i believe that these substances have a destructive action on the reductases1 most complete in the case of chloroform4 ,dubois 7#aiai;c7 also has recorded the occurrence of a reducing enzyme in ,pholas1 a hydrogenase1 which is able to form hydrogen from cane sugar1 and luciferin from a boiled extract of ,pholas4 ,he now regards it as identical with his co-luciferase4 ,i have not been able to demonstrate that a ,cypridina extract will reduce methylene blue1 or nitrates to nitrites1 either with or without the addition of acetaldehyde4 ,this may be due to the fact that oxyluciferin1 which is also present1 may be reduced more readily than either nitrates or methylene blue1 and so is reduced first4 ,we can also reduce oxyluciferin by means which do not involve the use of animal extracts4 ,perhaps the best of these is reduction by palladium black and sodium hypophosphite4 ,the latter is oxidized in presence of palladium and nascent hydrogen is set free4 ,the nascent hydrogen reduces any easily reducible substance which may be present1 such as methylene blue or oxyluciferin4 ,oxyluciferin is not reduced by palladium alone or hypophosphite alone1 but methylene blue is reduced by palladium black alone4 ,if hydrogen sulphide is passed through a solution of methylene blue the dye is very quickly reduced and becomes colorless4 ,if the ,h#b,s is driven off by boiling the colorless methylene-blue solution1 the blue color again returns on cooling4 ,oxyluciferin can also be reduced by ,h#b,s4 ,if one adds some ,mg powder to oxyluciferin and then dilute acetic acid in successive additions as the acetic acid is used up in formation of ,mg acetate1 the oxyluciferin will be reduced relatively quickly4 ,nascent hydrogen is produced in the reaction and is no doubt the active reducing agent4 ,dilute acid favors the reduction of oxyluciferin4 ,if one saturates an oxyluciferin solution with ,,co#b or adds a little dilute acetic acid1 ,h,cl1 ,,hno#c or ,h#b,,so#d1 to it1 a certain amount of reduction will occur4 ,no reduction occurs if the solution is saturated with pure hydrogen1 even if allowed to stand #bd hours4 ,the action of the acid begins when the solution of oxyluciferin1 ordinarily slightly alkaline 7,,ph #i71 is made neutral 7,,ph #g4a7 as indicated in ,table #i4 ,the action of the acid must be on the oxyluciferin1 as no luciferin or other enzymes destroyed on boiling are present4 ,,table #i ,effect of ,acid on ,reduction of ,oxyluciferin ,solution ,p,h,luminescence ,remarks with luciferase ---------------------------------------- ---------------------------------- #bj c4c4 ,oxyluciferin alone #i4ja ,negative #bj c4c4 ,oxyluciferin 4#je c4c4 #h4h ,negative #e per cent4 acetic acid #bj c4c4 ,oxyluciferin 4#ae c4c4 #g4a ,fair #e per cent4 acetic acid #bj c4c4 ,oxyluciferin 4#cj c4c4 #e4i ,good ,acid forms precipitate in #e per cent4 acetic acid this oxyluciferin sol4 #bj c4c4 ,oxyluciferin 4#ej c4c4 ,good ,acid forms precipitate in #e per cent4 acetic acid this oxyluciferin sol4 #bj c4c4 ,oxyluciferin 4#ge c4c4 ,good #aj ,acid forms precipitate in #e per cent4 acetic acid this oxyluciferin sol4 ---------------------------------------- ---------------------------------- #aj ,light disappears quickly because of the effect of the acidity on the luciferase4 ,it is possible that the action of bacteria 7which produces ,,co#b71 muscle tissue 7which contains lactic acid71 milk 7in which lactic acid may be formed by bacteria71 or ,mg acid1 in forming luciferin1 is not the result of their reducing power but of their acidity4 ,fortunately we can test this matter by the use of reducing fluids which are not acid4 ,if they also form luciferin from oxyluciferin1 a reduction must occur4 ,nascent ,h can be generated by the action of ,na,o,h on ,al1 or when finely divided ,mg or ,zn or ,al is placed in water4 ,with ,mg the water becomes only slightly alkaline from formation of almost insoluble ,mg7,,oh7#b4 ,if we add some ,al powder and dilute ,na,o,h to an oxyluciferin solution1 ,h is given off and luciferin is formed4 ,as oxyluciferin cannot be formed by the addition of alkali alone we must have in this experiment a reduction of oxyluciferin in alkaline medium by the nascent ,h produced4 ,luciferin can also be formed by merely adding ,al or ,zn or ,mg dust to an oxyluciferin solution4 ,methylene blue can also be readily reduced to its leuco-base by ,zn dust or ,al ,na,o,h4 ,indeed1 if one adds some ,al or ,zn or ,mg powder to a solution of luciferase1 light will appear whenever the solution is shaken4 ,luciferase solution must always contain the oxidation product of luciferin1 oxyluciferin4 ,in presence of nascent ,h this is reduced to luciferin1 and since the reaction of the medium is alkaline and luciferase is present this is oxidized with light production1 when1 by shaking1 air is dissolved4 ,the light can never become very bright except at the surface because of the deficiency of oxygen in the solution4 ,it would seem1 then1 that the action of bacteria1 yeast1 muscle cells1 etc41 on oxyluciferin must be due not entirely to their acid reaction but to their reducing power as well4 ,the above experiment is a very striking and instructive one4 ,given a test tube of luciferase solution containing1 as it does1 oxyluciferin1 add some ,zn dust or ,mg powder1 and the evolution of hydrogen begins4 ,conditions are now favorable for the reduction of oxyluciferin and this occurs4 ,shake the contents of the tube to dissolve oxygen and light appears4 ,allow the tube to stand and the light soon disappears4 ,shake again and the light reappears4 ,the luminescence reduction and oxidation process can be demonstrated many times4 ,a similar experiment can be performed with luciferase and oxyluciferin solution by addition of ,,nh#d,,sh4 ,this will serve also as another example of the reduction of oxyluciferin in an alkaline medium4 ,whenever we shake a tube of luciferase1 oxyluciferin and ,,nh#d,,sh1 light will appear4 ,when the tube is at rest it becomes dark4 ,even the merest touch is sufficient to agitate the tube contents1 cause solution of oxygen and appearance of light4 ,it is just as if we stimulate the tube to produce light and ,i believe the phenomenon has a deeper significance and a more fundamental similarity to the phenomena of stimulation than may at first appear4 ,what more simple means of controlling a process can we think of than by admission or withdrawal of oxygen8 ,the firefly turns on its light by stimulation through nerves of the luminous organ4 ,noctiluca flashes on stimulation of any kind1 even the slightest agitation causing a brilliant emission of light4 ,if the stimulation process means merely the admission of oxygen to the photogenic cells we have a mechanism in the cell itself for automatically producing the light4 ,the admission of oxygen results in aerobic conditions and luciferin in presence of luciferase can then oxidize to oxyluciferin with luminescence4 ,when the oxygen is used up1 the light ceases1 anaerobic conditions prevail1 and the oxyluciferin is reduced to luciferin again4 ,thus1 luciferin is reformed during the rest period of ,noctiluca or between the flashes of the firefly4 ,what more efficient type of light than this is to be desired8 ,again1 methylene blue offers an interesting parallel to oxyluciferin4 ,a little ,,nh#d,,sh added to methylene blue solution will reduce 7decolorize7 it to the leuco-base4 ,if the tube is now shaken the blue color returns4 ,on standing reduction again occurs4 ,the process can be repeated a number of times1 the reaction going in one or the other direction1 depending on the oxygen content of the mixture4 ,as methylene blue contains no oxygen1 its reduction consists in the addition of two atoms of hydrogen4 ,when leuco-methylene blue oxidizes1 water is formed by the union of these two atoms of hydrogen with oxygen1 thus3 ,c#af;,h#bj,n#c,s,cl ,o ,c#af;,h#ah,n#c,s,cl ,h#b,o 7leuco-methylene blue7 7methylene blue7 ,briefly--,,mh#b ,o ,m ,h#b,o ,to reduce methylene blue we can add the two hydrogen atoms directly from nascent hydrogen formed in the solution or we can split up water by a catalyzer in the presence of some substance1 which will take up the oxygen of water1 thus3 ,na,h#b,,po#b ,h#b,o ,pd ,na,h#b,,po#c ,h#b ,pd 7,sodium hypophosphite7 7,sodium phosphite7 ,this reaction occurs in presence of finely divided palladium4 ,methylene blue can be reduced by the ,h#b and the hypophosphite oxidized4 ,since oxyluciferin can be reduced by palladium and sodium hypophosphite 7,harvey1 #aiah71 it is probable that we can write the equation for reduction of oxyluciferin and oxidation of luciferin in a similar manner to that of methylene blue3 ,luciferin ,o ,oxyluciferin ,h#b,o ,briefly--,,lh#b ,o ,l ,h#b,o4 ,just as in the case of methylene blue the reaction proceeds in the right hand direction spontaneously if the pressure of ,o is sufficiently high4 ,if luciferase is also present we have luminescence4 ,,lh#b ,o luciferase ,l ,h#b,o luciferase 7luminescence7 ,the reaction proceeds in the left hand direction under low oxygen pressure1 in the presence of nascent hydrogen or with some catalyzer which is able to split water1 transferring the ,h#b to oxyluciferin and the ,o to an acceptor 7,a74 ,na,h#b,,po#b plays the part of the acceptor4 ,l ,h#b,o ,a ,pd ,,lh#b ,,ao ,pd4 ,this appears to be the way in which the reducing enzymes or perhydridases 7comparable to the ,pd7 of living tissues act 7,bach1 #aiaa-ac7 and the action of yeast cells1 bacteria1 muscle suspensions1 etc41 in reducing oxyluciferin must occur in the same manner4 ,if we assume that the ,,lh#b 7luciferin7 compound is dissociated to even the slightest extent into ,l and hydrogen1 the hydrogen ion will shift the equilibrium toward the formation of that substance which involves the taking up of hydrogen4 ,consequently we may obtain a partial formation of luciferin by adding an acid to oxyluciferin4 ,reduction of the ,h-ion concentration tends to shift the equilibrium in the opposite direction4 ,consequently1 addition of alkali favors the oxidation of luciferin1 and it is quite generally true that biological oxidations are favored by an alkaline reaction4 ,in addition oxygen in alkaline medium has a higher oxidation potential than in neutral or acid media4 ,i believe this is the explanation of the action of acid in formation of luciferin from oxyluciferin4 ,addition of acid is not the only means of favoring the formation of luciferin from oxyluciferin4 ,any reaction which proceeds in one direction with evolution of light should1 theoretically1 proceed in the opposite direction under the influence of light4 ,so far as ,i know the case of a reaction1 photogenic in one direction and photochemical in the other direction1 has never been described1 unless we are to accept the cases of phosphorescence1 for instance1 the absorption of light by ,ca,s and its emission in the dark4 ,however1 the reaction which occurs during phosphorescence cannot be stated4 ,it is a fact that light will cause the reduction of oxyluciferin4 ,a tube of oxyluciferin exposed to sunlight for six hours1 or the mercury arc for two hours1 will be partially converted into luciferin4 ,it will luminesce when luciferase is added1 while a control tube kept in darkness shows no trace of luciferin4 ,the action is more marked with the ultra-violet as a solution of oxyluciferin in a quartz tube showed more reduction than one in a glass tube when exposed for the same length of time to the quartz mercury arc4 ,the reduction is not dependent on the formation of acid under the influence of light since two tubes of oxyluciferin1 one kept in darkness and the other exposed to sunlight for six hours1 had the same reaction1 ,,ph #i4c4 ,of course some reducing substance might be formed under the influence of light but this is not very probable4 ,we may therefore write the reaction for luminescence in the following way3 darkness alkali luciferase luciferin 7,,lh#b7 ,o oxyluciferin 7,l7 ,h#b,o 7luminescence7 perhydridase acid light ,acid and light favor reduction while alkali and darkness favor oxidation in the luciferin oxyluciferin reaction4 ,whether the luciferin be really oxidized by removal of ,h#b or whether by addition of oxygen is1 of course1 uncertain1 but the analogy with methylene blue is striking and may serve as a working hypothesis until the composition of luciferin and its oxidation product are known4 ,while ,i have not studied the properties of oxyluciferin as fully as those of luciferin1 so far as ,i can judge1 both substances give the same general reactions and possess identical properties4 ,both crude luciferin and crude oxyluciferin solution are yellow in color1 but ,i do not believe that either pure luciferin or oxyluciferin are yellow in color1 because an ether or benzine extract of ,cypridina is also yellow1 although luciferase1 luciferin1 and oxyluciferin are insoluble in ether and benzine4 ,the yellow pigment which can be observed to make up part of the luminous gland of ,cypridina is not luciferin or luciferase4 ,it may be a pigment related to urochrome4 ,when tests are applied and precipitating reagents are added to crude luciferin and crude oxyluciferin solution1 they give identical results in each case4 ,a more complete account of the chemistry of luciferin has been given in this chapter1 and there is no need of duplicating these statements regarding oxyluciferin4 ,like luciferin1 the oxyluciferin will pass porcelain filters1 dialyze through parchment or collodion membranes1 and is undigested by salivary diastase1 pepsin ,h,cl1 ,merck's pancreatin in neutral solution1 and erepsin4 ,the salivary diastase and the pancreatin 7containing amylopsin1 trypsin1 and lipase7 were allowed to digest for four days at #ch deg4 ,c4 without showing any evidence of digestive action4 ,as luciferin is so easily oxidizable a substance1 we should expect to find that it will reduce just as glucose will reduce4 ,however1 a concentrated solution of luciferin has no reducing action on ,fehling's 7alkaline ,cu71 ,barfoed's 7acid ,cu71 ,nylander's 7alkaline ,bi7 or ,knapp's 7alkaline ,hg7 reagent4 ,glucose will reduce methylene blue in alkaline 7not in neutral solution71 but luciferin will not reduce methylene blue in alkaline or neutral solution4 ,it would seem1 then1 that luciferin must contain no aldehyde group4 ,if so1 we should expect to obtain reduction of some of the above reagents4 ,just what group is concerned in the oxidation is unknown at the present time1 and in the absence of more experimental data1 speculation regarding it can be of little value4 ,,summary ,in summing up we may say that the luminescence of at least three groups of luminous animals1 the beetles1 ,pholas1 and ,cypridina1 has been definitely shown to be due to the interaction of two substances1 luciferin and luciferase1 in presence of water and oxygen4 ,luciferin and luciferase have quite different properties and may be easily separated from each other by various chemical procedures4 ,as the luciferins and luciferases from different luminous animals have somewhat different properties1 they may be designated by prefixing the generic name of the animal from which they are obtained4 ,cypridina luciferin differs from ,pholas luciferin in that it can not be oxidized with light production by ,k,mn,o#d1 ,h#b,o#b1 with or without haemoglobin1 or similar oxidizing agents4 ,cypridina luciferase differs from ,pholas and firefly luciferase in that it is not readily destroyed by the fat-solvent anaesthetics1 such as chloroform1 ether1 etc4 ,when ,cypridina luciferin is oxidized1 no fundamental splitting of the molecule occurs1 because the product1 oxyluciferin1 can be readily reduced to luciferin again4 ,this reduction is brought about under conditions similar to those necessary for the reduction of dyes1 such as methylene blue4 ,oxyluciferin can be reduced to luciferin1 which will again give light with luciferase1 by the reductases of muscle tissue1 liver1 etc41 or by bacteria2 by ,schardinger's enzyme of milk2 by ,h#b,s2 by the nascent hydrogen from the action of acetic acid on magnesium or of water or ,na,o,h on aluminium1 zinc or magnesium2 and by palladium black and sodium hypophosphite1 all well-known reducing methods4 ,reduction of oxyluciferin no doubt occurs even in presence of luciferase if oxygen is absent1 and reduction of oxyluciferin no doubt occurs in animals which burn luciferin within the cell1 thus tending for conservation of material4 ,dilute alkali favors oxidation and dilute acid favors the reduction4 ,light favors the reduction of oxyluciferin4 ,apparently luciferin and oxyluciferin have identical chemical properties4 ,neither is digested by the enzymes3 malt diastase1 ptyalin1 yeast invertase1 pepsin1 trypsin1 steapsin1 amylopsin1 rennin1 erepsin1 urease or enzymes occurring in the water extracts of dried spleen1 kidney1 or liver4 ,luciferase is destroyed only by pepsin 7probably71 trypsin1 erepsin1 and something in spleen and liver extract4 ,luciferase is unquestionably a protein and all its properties agree with those of the albumins4 ,although used up in oxidizing large quantities of luciferin1 it behaves in many ways like an enzyme and may be so regarded4 ,luciferin1 on the other hand1 is not digested by proteolytic enzymes1 is dialyzable1 almost but not completely precipitated by saturation with 7,,nh#d7b,,so#d1 and is soluble in absolute alcohol1 acetone1 and some other organic solvents1 but not in the strictly fat-solvents like ether1 chloroform1 and benzol4 ,there are1 however1 certain ,,co-,,nh linkages which are not attacked by proteolytic enzymes and some peptones soluble in absolute alcohol1 so that these two characteristics do not bar it from the group of proteins4 ,luciferin1 in fact1 has many properties in common with the proteoses and peptones but its chemical nature cannot be definitely stated at present4 ,,chapter ,,vii ,,dynamics ,,of ,,luminescence ,one of the most extraordinary things regarding luminescence in general is the small amount of material necessary to cause a visible emission of light4 ,to take an extreme case1 the flash of light resulting from the impact on ,zn,s of a single alpha particle1 a helium atom1 is visible to the naked eye4 ,addition of one part in a million of some heavy metal to pure ,ca,s will confer phosphorescent properties on the latter4 ,we are forced to believe that the heavy metal enters into some reaction during illumination which is reversed with light emission after illumination and a very small amount of heavy metal is necessary4 ,pyrogallol in water1 #a3e1jjj1jjj 7m_/#eab1jjj71 can be oxidized with light production by ,k#d;,fe7,,cn7#f and ,h#b,o#b 7,harvey1 #aiag7 and m_/#ajj pyrogallol ,h#b,o#b will give a visible light with colloidal platinum in #a3bej1jjj concentration 7,goss1 #aiag74 ,luciferin and luciferase from ,cypridina will also luminesce in exceedingly small concentration4 ,if one grinds a single ,cypridina in a mortar with water and dilutes the extract to #be1fjj c4c41 light can be observed if luciferin is added to this dilute luciferase solution4 ,by determining the volume of the luminous gland of ,cypridina and even assuming that this volume is all luciferase1 one can calculate that one part of luciferase in #a1gjj1jjj1jjj parts of water will give light when luciferin is added4 ,likewise1 a similar dilution of luciferin will give visible light when luciferase is added4 ,the sensitivity of our eye is largely responsible for the detection of so small an energy change4 ,as we have seen1 recent determinations have proved that the dark adapted eye can detect #ah x #aj-aj ergs per second4 ,from the heat of complete oxidation of pyrogallol it is possible to calculate the amount of pyrogallol necessary to give #ah x #aj-aj ergs if completely oxidized4 ,this quantity is infinitesimally small4 ,when pyrogallol is oxidized by ,k#d;,fe7,,cn7#f and ,h#b,o#b1 it is not completely oxidized and probably only a small amount of the energy is converted into light2 otherwise we should be able to see the luminescence of a very much weaker concentration of pyrogallol4 ,as the reaction luciferin oxyluciferin is so easily reversible1 very little energy must be liberated1 and1 as experiments indicate1 very little heat1 if any1 accompanies light production4 ,even though this be true1 it is still possible for a very small amount of luciferin to produce a very large amount of light4 ,a very small amount of luciferase only is necessary because it behaves as an enzyme and follows the general rule that catalysts act in minute concentrations4 ,on the assumption that luciferase is an enzyme1 an organic catalyst oxidizing luciferin with light production1 we may appropriately inquire into the relation between the concentration of luciferin and luciferase and intensity and duration of luminescence4 ,oxygen tension1 hydrogen ion concentration and temperature must be maintained constant as these all affect both intensity and duration of luminescence4 ,before considering luciferin and luciferase1 however1 let us study a few well-known chemiluminescent oxidations with special reference to concentration of reacting substances and temperature4 ,the effect of temperature on luminescence is of special interest because it gives us a means of analysis for determining if the luminescence depends on reaction velocity4 ,we know that photochemical reactions are very little affected by temperature because the reaction is dependent on the absorption of light1 a physical process1 and this increases only a small per cent4 for a rise of temperature of #aj deg4 ,c4 ,to put it in the usual way1 its temperature coefficient 7,q#aj7 for a #aj deg4 interval is usually less than #a4a4 ,on the other hand1 we should expect photogenic reactions1 in which some of the chemical energy is converted into radiant energy1 to give off much more light the greater the reaction velocity4 ,as reaction velocity increases so rapidly with temperature 7,q#aj #b to #c71 luminescence intensity should rapidly increase with increase in temperature4 ,trautz 7#aije71 from his extensive study of the chemiluminescence of phenol and aldehyde compounds came to the conclusion that luminescence intensity was proportional to reaction velocity4 ,he based his conclusions largely on the effects of temperature and concentration of reacting substances and went so far as to declare that any reaction would produce luminescence if the reaction velocity were sufficiently increased4 ,it is quite true that increasing the temperature does increase the intensity of chemiluminescence1 but this is only within certain limits4 ,as we raise the temperature1 chemiluminescence becomes more intense but we soon reach a temperature for maximum luminescence and above this the intensity diminishes4 ,this is especially well seen in the action of various oxidizers on pyrogallol and ,h#b,o#b recorded in ,table #aj4 ,at #ajj deg4 ,c4 practically no light is produced by many oxidizers which are themselves unaffected at #ajj deg44 ,if we are to connect reaction velocity with intensity of luminescence we must conclude that the evolution of light is dependent rather on an optimum than a maximum reaction velocity4 ,,table #aj ,temperature and ,light ,production4 ,the ,oxidizer is ,mixed with an ,equal ,amount of ,m_/#ajj ,pyrogallol #c per cent4 ,h#b,o#b ,temperatures ,oxidizer ---------------------------------------- ------ #j-b deg4 #bj deg4 #ej deg4 #ge deg4 #ih-ajj deg4 ---------------------------------------- ---------------------------- ,turnip juice ,faint ,good ,good ,negative4 #a per cent4 blood extract ,faint ,fair ,good ,fair4 ,m_/#bj ,k#d;,fe7,,cn7#f ,negative ,good ,bright ,bright ,good4 ,m_/#ajj ,k,mn,o#d ,fair ,good ,bright ,bright ,faint flash4 ,m_/#ej ,k#b;,cr#b,o#g ,negative ,fair ,faint ,fair ,negative4 ,m_/#ajj ,cr,o#c ,negative ,good ,bright ,bright ,faint4 ,m_/#aj ,k,cr alum ,negative ,faint ,faint ,faint ,negative4 ,m_/#aj ,,nh#d;,fe alum ,negative ,faint ,faint ,faint ,very faint4 ,mn,o#b ,negative ,fair ,fair ,fair ,negative4 ,na,cl,o ,bright ,bright ,bright ,fair flash flash flash flash4 ---------------------------------------- ---------------------------- ,quite a number of instances are known in which increasing the mass of reacting substances leads not to an increase but to an actual cessation of luminescence4 ,this fact does not confirm the theory that reaction velocity is a determining factor in luminescence4 ,the conditions for the luminescence of white phosphorus are most interesting and unusual4 7,see van't ,hoff1 #ahie2 ,ewan1 #ahie2 ,centnerszwer1 #ahie2 ,russell1#aijc2 ,scharff1 #aijh47 ,phosphorus will only begin to luminesce at a certain small pressure of oxygen4 ,this minimum luminescence pressure of oxygen is very low1 so low that earlier observers1 failing to remove traces of oxygen1 thought that luminescence might occur in absence of oxygen4 ,curiously enough there is also a maximum luminescence pressure of oxygen above which no luminescence occurs4 ,phosphorus will not luminesce in pure oxygen4 ,between the minimum and maximum is an optimum luminescence pressure where luminescence of the phosphorus is brightest4 ,the exact values of these pressures vary with degree of water vapor present and with temperature4 ,according to ,abegg's ,handbuch der anorganischen ,chemie1 the maximum luminescence pressure with water vapor present1 is #cbj mm4 ,hg at #j deg4 and increases #ac4ai mm4 ,hg for each degree rise in temperature4 ,this means that for a definite temperature1 say1 #bj deg41 phosphorus will not luminesce with an oxygen pressure of #ehc mm4 ,hg1 but will luminesce with pressures under this4 ,if1 however1 we raise the temperature1 luminescence will occur with an oxygen pressure of #ehc mm4 ,hg4 ,a somewhat analogous case is presented by the oxidation of pyrogallol solution in contact with ozone1 except that in this reaction too high a concentration of pyrogallol will hinder the oxidation4 ,i have not studied the effect of varying concentrations of ozone4 ,if oxygen1 passed through an ozonizer 7the silent electric discharge tube71 is bubbled through m_/#ajj pyrogallol1 no luminescence occurs at #j deg41 a fair luminescence at #bj deg41 a good luminescence at #ej deg41 and a bright luminescence at the boiling point4 ,if the pyrogallol is of m concentration1 no luminescence occurs at #j deg4 or #bj deg41 a fair luminescence at #ej deg41 and a bright luminescence at the boiling point4 ,for a definite temperature1 say #bj deg41 no light appears if the pyrogallol is of m concentration1 but if we raise the temperature1 luminescence can occur4 ,the similarity to phosphorus is obvious4 ,thus the maximum luminescence pressure of pyrogallol increases with increase of temperature4 ,we have already seen that pyrogallol can also be oxidized1 if ,h#b,o#b is present1 by a great variety of substances1 such as peroxidases of potato or turnip juice1 haemoglobin1 ,k,mn,o#d1 ,k#d;,fe7,,cn7#f1 ,cr,o#c1 ,mn,o#b1 hypochlorites and hypobromites1 or colloidal ,pt and ,ag4 ,for convenience we may collectively speak of these as oxidizers4 ,they are recorded in ,table #ac4 ,no light occurs if ,h#b,o#b;is absent4 ,in the case of some of these oxidizers pyrogallol will luminesce in dilute concentrations but not in strong4 ,also1 dilute pyrogallol will luminesce with a dilute solution of oxidizer but not with a concentrated solution of oxidizer4 ,the effect of rise in temperature in these cases also is to increase the maximum luminescence concentration of pyrogallol and the maximum luminescence concentration of oxidizer4 ,table #aa shows this effect of temperature with ,k#d;,fe7,,cn7#f and varying concentrations of pyrogallol1 and ,table #ab shows the effect of temperature with pyrogallol and varying concentrations of ,k#d;,fe7,,cn7#f4 ,table #aj shows the relation between temperature and intensity of luminescence with pyrogallol and various oxidizers4 ,the terms faint1 fair1 good1 and bright are purely relative designations of brightness as estimated by the eye1 for accurate measurements of weak intensities are very difficult to make4 ,from ,table #aj it should be noted that the intensity of luminescence of pyrogallol oxidized with most oxidizers is actually less at the boiling point1 a fact which ,i have repeatedly verified4 ,let us now see how these facts are to be explained4 ,if we assume that luminescence is dependent on reaction velocity1 the intensity of luminescence should increase with increasing temperature4 ,up to a certain limit this is what we find1 but at temperatures above this limit the intensity of luminescence actually decreases4 ,the duration of luminescence also decreases4 ,there is an optimum temperature for luminescence in many cases and we can only conclude that luminescence depends not on a very rapid reaction velocity but on a certain definite reaction velocity4 ,assuming that this is true1 how can we account for the anomalous fact that in high concentrations of oxygen1 phosphorus will not luminesce or that in high concentrations of pyrogallol1 there is no luminescence in presence of ozone or of oxidizer and ,h#b,o#b4 ,of course with high active mass of oxygen 7in case of phosphorous luminescence7 or of pyrogallol 7in case of pyrogallol luminescence7 the reaction velocity must be greater than the optimum4 ,if that is the case1 then lowering the temperature should reduce the reaction velocity to the optimum and light should appear4 ,however1 as we have seen1 not lowering but raising the temperature causes luminescence with high oxygen concentration or high pyrogallol concentration4 ,,table #aa ,temperature1 ,concentration of ,pyrogallol1 and ,light ,production4 ,an ,equal ,amount of ,m_/#bj ,k#d;,fe7,,cn7#f is ,mixed with ,pyrogallol #c per ,cent ,h#b,o#b ,a ,concentration of pyrogallol 7after mixing7 ,temperatures ,a ---------------------------------------- ------------------ #j-b deg4 #aj deg4 #bj deg4 #cj deg4 #ej deg4 #ge deg4 #ih-ajj deg4 ---------------------------------------- -------------------------- ,m_/#d ,negative ,negative ,good ,very ,faint ,fair ,faint faint ,m_/#dj ,negative ,faint ,faint ,faint ,good ,bright ,good ,m_/#djj ,faint ,fair ,good ,good ,good ,bright ,bright flash ,m_/#d1jjj ,bright ,bright ,bright ,bright ,bright ,fair ,negative flash flash ---------------------------------------- -------------------------- ,,table #ab ,temperature1 ,concentration of ,ferrocyanide and ,light ,production4 ,an ,equal ,amount of ,k#d;,fe7,,cn7#f is ,mixed with ,m_/#ajj ,pyrogallol #c ,per ,cent ,h#b,o#b ,a ,concentration of ,k#d;,fe7,,cn7#f exposed to light 7after mixing7 ,temperatures ,a ---------------------------------------- ----- #j-b deg4 #aj deg4 #bj deg4 #cj deg4 #ej deg4 #ge deg4 #ih-ajj deg4 ---------------------------------------- ------------------------- ,half saturated ,negative ,faint,fair ,fair ,good ,good ,faint at #bj deg4 ,c flash ,one-sixth saturated ,very ,fair ,good ,good ,bright,very ,good at #bj deg4 ,c faint bright flash ---------------------------------------- ------------------------- ,,table #ac ,substances ,giving ,light with ,pyrogallol and ,hydrogen ,peroxide ,key to column headings3 ,a ,equal volume added to mixture of #a part ,m_/#ajj pyrogallol or #a part #c per cent ,h#b,o#b #a part ,m_/#ajj pyrogallol2 hence1 concentrations final mixture are one-half that given ,b ,light with pyrogallol ,c ,light with pyrogallol ,h#b,o#b ,d ,blueing of gum guaiac ,e ,blueing of gum guaiac ,h#b,o#b ,f ,liberation of oxygen from ,h#b,o#b ,a ,b ,c ,d ,e ,f ---------------------------------------- -------------------------------- #a ,potassium ferrocyanide - ,bright 7,k#d;,fe7,,cn7#f ,m_/#aj-,m_/#bj7 #b ,potassium ferricyanide - ,very - - ,very 7,k#c;,fe7,,cn7#f ,m_/#aj-,m_/#a1bej7 faint slow to - #c ,potassium chromate - ,good 7,k#b;,cr,o#d ,m_/#bj-,m_/#ajj7 #d ,potassium bichromate - ,good 7,k#b;,cr#b,o#g ,m_/#ej-,m_/#ajj7 #e ,potassium permanganate - ,bright - 7,k,mn,o#d ,m_/#ej-,m_/#bjj7 #f ,potassium hydroxide - - - - ,very 7,,koh ,m-,m_/#f1bej7 slow #g ,potassium chlorate - - - - - 7,k,cl,o#c ,m_/#aj7 #h ,potassium persulfate - - - - - 7,k#b,s#b,o#h ,m_/#aj-,m_/#abh7 #i ,potassium chromium alum - ,faint ,very ,very - 7,cr#b7,,so#d7c4,k#b,,so#d ,m_/#aj7 slow slow #aj ,ferric ammonium alum - ,faint ,very 7,fe#b7,,so#d7c47,,nh#d7b,,so#d slow ,m_/#aj7 #aa ,ferric chloride - ,fair ,slow 7,fe,cl#c ,m_/#aj-,m_/#bej7 #ab ,ferrous sulfate - ,fair - ,slow 7,fe,s,o#d ,m_/#aj-,m_/#f1bej7 #ac ,copper sulfate - - - ,very 7,cu,s,o#d ,m_/#e-,m_/#abe7 slow #ad ,chromic acid - ,bright 7,cr,o#c ,m_/#ajj7 #ae ,chromic sulfate - ,faint - ,slow 7,cr#b7,,so#d7c #b per cent7 #af ,chlorine water - - #ag ,bromine water - - #ah ,iodine in ,,ki - - #ai ,sodium hypochlorite ,faint ,bright 7,cl water ,na,o,h7 flash #bj ,sodium hypobromite ,faint ,bright 7,na,o,br1 bromine water ,na,o,h7 flash #ba ,sodium hypoiodite - ,faint 7,i in ,,ki ,na,o,h7 #bb ,calcium hypochlorite - ,good 7,ca7,o,cl7#b saturated solution7 #bc ,turnip juice - ,bright - #bd ,turnip juice heated to #gj deg4 - ,faint - ,very slow #be ,turnip juice boiled - - - - - #bf ,albumin solution - - - - - #bg ,albumin solution ,k,mn,o#d - ,good - #bh ,albumin solution ,k,mn,o#d boiled #a min4 and filtered 7no precipitate forms7 - ,good - #bi ,gelatin solution - - - - - #cj ,gelatin solution ,k,mn,o#d - ,good - - #ca ,gelatin solution ,k,mn,o#d boiled #a min4 and filtered 7no precipitate forms7 - ,good - #cb ,colloidal ,ag - ,bright #cc ,colloidal ,pt - ,bright #cd ,colloidal ,fe7,,oh7#b 7dilute7 - - - - #ce ,sodium nucleoproteinate 7liver7 - - - - #cf ,sodium nucleoproteinate 7mammary gland7 - - - - - #cg ,sodium nucleate 7yeast7 - - - - - #ch ,squid blood 7,sepia esculenta74 ,contains hemocyanin - ,fair #ci ,squid blood 7,sepia esculenta7 boiled - ,good - #dj ,lobster blood 7,palinurus japonicus74 ,contains hemocyanin and tetronerythrin1 a lipochrome - ,faint #da ,lobster blood 7,palinurus japonicus7 boiled - ,fair - #db ,annelid blood 7,laonome japonica74 ,contains chlorocruorin - ,good #dc ,annelid blood 7,laonome japonica7 boiled - - #dd ,luminous pennatulid extract 7,cavernularia haberi7 - - - #de ,luminous ostracod extract 7,cypridina hilgendorfii7 - - #df ,luminous protozoan extract 7,noctiluca miliaris7 - - - - - #dg ,firefly 7,luciola viticollis7 extract1 luminous organs - - #dh ,ferrous ferrocyanide 7,fe#b;,fe7,,cn7#f7 - ,faint #di ,zinc ferrocyanide 7,zn#b;,fe7,,cn7#f7 - - ,very slow #ej ,chromic oxide 7,cr#b,o#c7 - - - ,slow #ea ,chromic hydroxide 7,cr7,,oh7#b7 - - - ,slow #eb ,manganese dioxide 7,mn,o#b7 - ,good ,slow ,slow ---------------------------------------- -------------------------------- ,i believe the explanation of these phenomena lies rather in another direction and that the effect of the temperature and concentration of reacting substances affects not only the reaction velocity but also the reaction products4 ,while intensity of luminescence undoubtedly increases with increasing reaction velocity1 the luminescence itself probably accompanies only one stage in the formation of a series of oxidation products4 ,this stage is favored at a definite temperature and mass of reacting substances4 ,thus1 in the oxidation of phosphorus several intermediate oxides are said to be formed4 ,the oxidation takes place in steps and probably the luminescence is connected with only one of the steps in a chain of reactions4 ,it is probable that a certain oxygen pressure and temperature favors that particular step at the expense of the others and so this oxygen concentration and temperature correspond to the optimum for luminescence4 ,the supposition that certain definite oxidation products of pyrogallol must be formed in order to produce light is borne out by the fact that pyrogallol must be oxidized in a particular way to obtain luminescence4 ,the blackening of pyrogallol with absorption of oxygen in presence of alkali is a very well-known reaction1 but luminescence does not accompany this type of oxidation4 ,i have tried mixing all concentrations of pyrogallol and all concentrations of alkali in an endeavor to obtain some light1 but always with negative results4 ,likewise my attempts to obtain light during the electrolysis of salt solutions containing pyrogallol by means of the nascent oxygen at various kinds of anodes have met with negative results4 ,a similar case is presented by luciferin which oxidizes spontaneously 7most rapidly in presence of alkali7 without light production and only produces light when oxidized in presence of luciferase4 ,to sum up the results of the dynamics of chemiluminescence we may say that certain oxyluminescences occur only if the substance is oxidized in a particular way under definite conditions of temperature and concentration and that this is probably due to a favoring of one step 7with which the luminescence is associated7 in a chain of oxidations4 ,providing temperature and concentration are such as to favor the step responsible for luminescence1 then higher temperature and greater concentration result in increased intensity of luminescence4 ,let us now turn to luminous organisms and consider the effect of temperature and of concentration of reacting substances 7oxygen1 luciferin and luciferase7 on the luminescence4 ,we have already seen that luminescence of a luciferin-luciferase mixture begins with an extraordinarily low oxygen tension and increases in intensity with increasing tension of oxygen1 but that very soon an oxygen tension is reached where a maximum luminescence is obtained and further increase of oxygen tension gives no brighter light4 ,in this respect the luminescence intensity--oxygen tension curve is no doubt very similar to the haemoglobin saturation--oxygen tension curve4 ,haemoglobin is about #ej per cent4 saturated at #aj mm4 oxygen pressure1 #hj per cent4 saturated at #bj mm4 oxygen pressure and completely saturated at pressures of oxygen well below the pressure of oxygen in air 7#aeb mm4 ,hg74 ,as the optimum oxygen tension for luminescence of luciferin is also well below that of air1 mixtures of luciferin and luciferase luminesce with equal brilliancy whether air or pure oxygen is bubbled through them4 ,to obtain an excess of oxygen it is only necessary to keep the solution saturated with air and statements regarding concentration of luciferin and luciferase and intensity or duration refer to excess of oxygen4 ,investigators who have studied the effect of increase in oxygen pressure on luminous animals have come to the same conclusions4 ,high pressures of air or oxygen do not increase the intensity of luminescence 7,dubois and ,regnard1 #ahhd74 ,the hydrogen ion concentration of crude solutions of luciferin and luciferase1 made by extracting whole ,cypridinas with hot or cold water is fairly constant1 about ,,ph #i1 determined electrometrically4 ,such solutions have a high buffer value and the ,,ph does not change during oxidation of luciferin so that this variable is automatically controlled4 ,because of difficulties in measuring low intensities of light which are constantly changing1 no figures on light intensities can be given1 but it is easy to establish the following facts3 ,the greater the concentration of luciferin or luciferase the more intense the luminescence4 ,the greater the concentration of luciferin the longer the duration of luminescence and the greater the concentration of luciferase1 the shorter the luminescence lasts4 ,thus1 if we mix concentrated luciferin and weak luciferase we get a bright light which lasts for a half hour or more1 gradually growing more dim4 ,concentrated luciferase and weak luciferin give a bright flash of light which disappears almost instantly4 ,concentrated luciferase and concentrated luciferin give a brilliant light which lasts for an intermediate length of time and weak luciferin and weak luciferase give a faint luminescence which lasts for an intermediate length of time4 ,these facts can all be explained by regarding luciferase as a catalyzer which accelerates the oxidation of luciferin and by assuming that intensity of luminescence is dependent on reaction velocity1 i4e41 on rate of oxidation4 ,contrary to the condition for phosphorus and for pyrogallol there appears to be no optimum concentration of luciferase or luciferin1 but the luminescence intensity increases gradually with increasing concentration of luminous substances up to the point where pure 787 luciferin and pure 787 luciferase1 as secreted from the gland cells of the animal1 come in contact with each other4 ,this1 the maximum brightness1 is not to be compared with the light of an incandescent solid1 but is nevertheless visible in a well-lighted room1 out of direct sunlight4 ,the effect of temperature on ,cypridina luminescence also bears out the preceding conclusions4 ,for a given mixture of luciferin and luciferase the light becomes more intense with increasing temperature up to a definite optimum and then diminishes in intensity4 ,the diminution in intensity above the optimum is due to a reversible change in the luciferase so that its active mass diminishes4 ,this change becomes irreversible in the neighborhood of #gj deg4 7depending on various conditions71 where coagulation of luciferase occurs4 ,light will appear at #j deg4 but it is far less intense than light at higher temperatures and it is more yellow in color4 ,the light of optimum temperatures is quite blue4 ,the weaker light at temperatures above the optimum is also more yellow in color4 ,i believe this difference in color is a function of the slowed reaction velocity1 for a mixture of luciferin and luciferase which gives a bluish luminescence at room temperature1 will give a weaker and yellowish luminescence if diluted with water4 ,dilution with water will slow the reaction velocity4 ,if the difference in color were not real but due to change in color sensitivity of the eye with different intensities of such relatively weak light 7,purkinje phenomenon71 the weaker light should appear more blue4 ,as the weaker light appears more yellow1 ,i therefore believe the color difference is actual and not subjective4 ,a minimum1 optimum1 and maximum temperature for luminescence is observed in all luminous organisms4 ,the minimum is usually very low4 ,luminous bacteria will still light at -#aa4e deg4 ,c4 ,the power to luminesce under ordinary conditions is not destroyed by exposure to liquid air1 for1 on raising the temperature1 light again appears 7,macfayden1 #aijj1 #aijb74 ,almost all organisms will luminesce at #j deg4 ,c41 and the luminescence minimum probably represents the point at which complete freezing of the luminous solution occurs4 ,it is very low with bacteria because they are solutions in capillary spaces of very small size1 a condition tending to lower the freezing point4 ,the luminescence maximum represents the point at which luciferase is reversibly changed so as to be no longer active4 ,if the temperature is again lowered the luciferase again becomes active and light reappears4 ,some degrees above this1 and in all forms well below the boiling point1 luciferase is coagulated and destroyed4 ,as the coagulation point of proteins depends on many factors1 such as time of heating1 salt content1 acidity1 etc41 so the luciferases of different animals coagulate at different temperatures depending on these conditions4 ,some of the more reliable observations on these critical temperatures are collected in ,table #ad4 ,,table #ad ,temperature ,limits of ,luminescence for ,luminous ,organism ---------------------------------------- --------------------------- ,organism ,author and date ,minimum,optimum,maximum ---------------------------------------- --------------------------- ,pseudomonas javanica ,eijkman1 #ahib -#bj deg4 #be-cc deg4 #de deg4 ,bacterium phosphorescens ,lehmann1 #ahhi -#ab deg4 444 #ci4e deg4 ,bacterium phosphoreum ,molish1 #aijd1 book -#e deg4 #af-ah deg4 #bh deg4 ,light bacteria ,tarchanoff1 #aijb -#g deg4 #ae-be deg4 #cg deg4 ,light bacteria ,harvey1 ,e4 ,n41 #aiac -#aa4e #ae-bj deg4 #ch deg4 ,mycelium ,x ,molish1 #aijd 444 #ae-be deg4 #cf deg4 ,lampyrids ,macaire1 #ahba -#aj #cc deg4 #df-ej deg4 ,pyrophorus noctilucus ,dubois1 #ahhf 444 #bj-be deg4 #dg deg4 ,photuris pennsylvanica ,lund1 #aiaa 444 444 #ej deg4 ,luciola viticollis ,harvey1 ,e4 ,b41 #aiae #j deg4 444 #db deg4 ,cypridina hilgendorfii ,harvey1 ,e4 ,n41 #aiae #j deg4 444 #eb-ed deg4 ,cyclopina gracilis ,lund1 #aiaa 444 444 #ej deg4 ,phylirrhoe bucephalum ,panceri1 #ahgb #dd deg4 444 #fa deg4 ,pyrosoma ,panceri1 #ahgb #j deg4 444 #fj deg4 ,mnemiopsis ,leidyi ,peters1 #aije #i deg4 #ba deg4 #cg deg4 ,noctiluca miliaris ,quatrefages1 #ahej #a deg4 444 #dj deg4 ,noctiluca miliaris ,harvey1 ,e4 ,b41 #aiag #j deg4 444 #dh deg4 ,cavernularia haberi ,harvey1 ,e4 ,n41 #aiae #j deg4 444 #eb deg4 ,watasenia scintillans ,shoji1 ,r1 #aiai 444 #af-ca deg4 #di deg4 ---------------------------------------- --------------------------- ,we are thus led to the conclusion that intensity of luminescence is dependent on the velocity of oxidation of luciferin and that with lowered reaction velocity the spectral composition of the light changes4 ,the maximum emission shifts toward the yellow4 ,i believe1 however1 that in ,cypridina also1 the luminescence intensity depends not only on reaction velocity but on the particular manner in which luciferin is oxidized4 ,cypridina luciferin will luminesce only in presence of ,cypridina luciferase and no light can be obtained from ,cypridina luciferin and a host of different oxidizers 7with or without ,h#b,o#b7 such as are able to oxidize pyrogallol4 ,luciferin will also oxidize in the air spontaneously but no light is produced4 ,it is easy to show that this spontaneous oxidation may be much more rapid than an oxidation with luciferase and yet light appears only in presence of the latter4 ,if a concentrated solution of luciferin is kept near the boiling point it will be completely oxidized to oxyluciferin in four or five minutes4 ,no light appears if air or even if pure oxygen is bubbled through it4 ,the same solution kept at #bj deg4 with a small amount of luciferase will luminesce continuously and not be completely oxidized to oxyluciferin in a half hour4 ,we can1 however1 cause the luciferin to oxidize as rapidly at #bj deg4 by adding concentrated luciferase as does the luciferin near the boiling point without luciferase4 ,a bright light is produced in the former case1 none in the latter case4 ,the oxyluciferin formed from spontaneous oxidation of luciferin appears to be the same as that formed with luciferase present4 ,both give luciferin again on reduction4 ,perhaps the reaction takes place in two stages1 similar to those supposed to occur in other enzyme actions3 luciferin luciferase luciferinluciferase luciferinluciferase ,o 7or minus ,h#b7 oxyluciferin luciferase4 ,we may then assume as a tentative hypothesis that luminescence only occurs during oxidation 7addition of ,o or removal of ,h7 of the luciferinluciferase compound4 ,we have just seen that the effect of cooling a ,cypridina extract containing luciferin and luciferase and luminescing with a bluish light1 is to reduce the intensity and change the shade toward the yellow4 ,velocity of oxidation must be lowered and with the same concentration of luciferase lowered velocity means more light of the longer wave-lengths4 ,a very instructive experiment on color of the light can be carried out with animals having different colored lights and so closely related that their luciferins and luciferases will interact with each other4 ,such a case is presented by the ,american fireflies1 ,photinus and ,photuris4 ,photinus emits an orange light1 while ,photuris emits a greenish yellow light4 ,the difference in color is especially noticeable when the luminous organs of the two forms are ground up in separate mortars4 ,as shown by ,coblentz1 the difference in color is real1 the spectrum of ,photinus extending farther into the red than that of ,photuris 7see ,fig4 #h74 ,we can easily prepare luciferin and luciferase from the two fireflies and make the following mixtures3 ,photinus luciferin x ,photinus luciferase reddish light4 ,photinus luciferin x ,photuris luciferase yellowish light4 ,photuris luciferin x ,photuris luciferase yellowish light4 ,photuris luciferin x ,photinus luciferase reddish light4 ,thus the color of the light in these crosses is that characteristic of the animal supplying the luciferase4 ,to bring this fact in line with what we have already said regarding reaction velocity and luminescence1 we must believe that the ,photinus luciferase oxidizes at a slower rate than the ,photuris luciferase4 ,in this connection it is of interest to recall that the ,photuris light as emitted by the insect becomes reddish at high temperatures1 or if the insect is plunged into alcohol1 both conditions which bring about partial coagulation of the luciferase and reduce its active mass4 ,,bibliography ,a few of the enormous number of papers on luminescence are included in the list below4 ,the attempt is made to list only those dealing with the structure1 chemistry or physiology of luminous animals and the physical nature of their light1 together with a small number of general interest4 ,more complete works on light and luminescence come first and original articles follow4 ,authors' names are arranged alphabetically1 their papers chronologically4 ,a fairly complete list of literature covering the whole field of ,bioluminescence is given by ,mangold1 #aiaj4 ,the #aiac paper of ,dubois gives a bibliography of his own contributions up to this date so that only those papers to which special reference is made are included below4 ,,books ,,and ,,general ,,works ,,becquerel1 ,e43 #ahfg1 ,la ,lumiere4 ,,dahlgren1 ,u43 #aiae1 ,the ,production of ,light by ,animals4 ,jour4 ,franklin ,inst41 vols4 #ahj to date4 ,,dubois1 ,r43 #aiad1 ,la ,vie et ,la ,lumiere4 ,alcan1 ,paris4 ,,gadean ,,de ,,kerville1 ,h43 #ahij1 ,les ,vegetaux et les ,animaux ,lumineux4 ,paris4 ,,harvey1 ,e4 ,n43 #aiag1 ,the ,chemistry of ,light ,production in ,luminous ,organisms4 ,carnegie ,inst41 ,wash41 ,pub4 ,no4 #bea1 pages #aga-bcd4 ,,heinrich1 ,pl43 #ahaa-ahbj1 ,die ,phosphorescenz der ,koerper1 etc4 ,nuernburg4 ,,houstoun1 ,r4 ,a43 #aiae1 ,a ,treatise on ,light4 ,london4 ,,kayser1 ,h43 #aijh1 ,handbuch der ,spectroscopie4 ,vols4 ii and iv4 ,leipzig4 ,,mangold1 ,e43 #aiaj1 ,die ,produktion von ,licht4 ,hans ,winterstein's ,handbuch der vergleichende ,physiologie1 vol4 iii1 second half1 pp4 #bbe-cib4 ,jena4 ,,molish1 ,h43 #aijd and #aiab1 ,leuchtende ,pflanzen4 ,eine physiologische ,studie4 ,jena4 ,,nutting1 ,p4 ,g43 #aiab1 ,outlines of ,applied ,optics4 ,philadelphia4 ,,phipson1 ,t4 ,l43 #ahgj1 ,phosphorescence4 ,l4 ,reeve and ,co4 ,london4 #baj pages4 ,,shepard1 ,s4 ,e41 #aiad1 ,photochemistry4 ,longmans1 ,green and ,co4 ,,original ,,papers ,,abegg1 ,r41 and ,,auerbach1 ,f43 #aijg1 ,handbuch der anorganischen ,chemie4 ,leipzig1 vol4 iii1 pt4 #c1 p4 #cgf4 ,,agassiz1 ,a43 #ahgd1 ,embryology of the ,ctenophorae4 ,mem4 ,am4 ,ac4 ,arts and ,science1 x1 p4 #cga4 ,,allman1 ,g4 ,i43 #ahfb1 ,note on the ,phosphorescence of ,beroe4 ,proc4 ,roy4 ,soc4 ,edinb41 iv1 #eah4 ,,aubert ,,et ,,dubois1 ,r43 #ahhd1 ,sur les proprietes de la lumiere des pyrophores4 ,comp4 rend4 ,acad4 des ,sc41 vol4 xcix1 p4 #dgg4 ,,bach1 ,a43 #aiaa-aiac1 ,zur ,kenntnis der ,reduktionsfermente4 ,biochem4 ,zeit1 xxxi1 #ddc2 xxxiii1 #bhb2 xxxviii1 #aed2 lii1 #dab-dbb4 ,,baker1 ,j43 #agdc-agec1 ,the ,microscope ,made ,easy and ,employment for the ,microscope4 ,,ballner1 ,f43 #aijg1 ,ueber das ,verhalten von ,leuchtbacterien bei der ,einwirkung von ,agglutinationsserum und anaesthesierenden chemischen ,agentien1 etc4 ,centralb4 f4 ,bact41 #b abt41 xix1 #egb4 ,,bancroft1 ,w4 ,d43 #aiac1 ,the ,chemical ,production of ,light4 ,journ4 ,frank4 ,inst41 clxxv1 #abi4 ,,bancroft1 ,w4 ,d41 and ,,weiser1 ,h4 ,b43 #aiad-aiae1 ,flame ,reactions1 ,i1 ,,ii1 ,,iii1 ,,iv4 ,jour4 ,phys4 ,chem41 xviii1 #bac1 #bha1 #gfb2 xix1 #caj4 ,,bandrowski1 ,e43 #ahid-ahie1 ,ueber ,lichterscheinungen waehrend der ,krystallisation4 ,zeit4 ,phys4 ,chem41 xv1 #cbc-cbf2 xvii1 #bcd-bdd4 ,,barcroft1 ,j41 and ,,hill1 ,a4 ,v43 #aiaj1 ,the ,nature of ,oxyhaemoglobin with a ,note on ,its ,molecular ,weight4 ,journ4 ,physiol41 xxix1 pp4 #daa-dbi4 ,,barnard1 ,j4 ,e43 #aijb1 ,luminous ,bacteria4 ,nature1 vol4 lxv1 p4 #ecf4 ,,beijerinck1 ,m4 ,w43 #ahhi;a1 ,le photobacterium luminosum1 bacterie lumineuse de la mer du nord4 ,arch4 ,neerlandaises1 ,t4 #bc1 p4 #ajd4 ,,beijerinck1 ,m4 ,w43 #ahhi;b1 ,l'auxanographie ou la methode de l'hydrodiffusion dans la gelatine appliquee aux recherches microbiologique4 ,arch4 ,neerlandaises1 vol4 xxiii1 p4 #cfg4 ,,beijerinck1 ,m4 ,w43 #ahhi;c1 ,les ,bacteries lumineuses dans leur rapports avec l'oxygene4 ,arch4 ,neerlandaises1 ,t4 #bc1 p4 #daf4 ,,beijerinck1 ,m4 ,w43 #ahia1 ,sur l'aliment photogene et l'aliment plastique des bacteries lumineuses4 ,arch4 ,neerlandaises1 ,t4 #bd1 pp4 #cfi-ddb4 ,,beijerinck1 ,m4 ,w43 #aijb1 ,photobacteria as a ,reactive in the ,investigation of the ,chlorophyll-function4 ,proceedings of ,section of ,sciences1 ,koninkl4 ,akad4 van ,wetenschappen te ,amsterdam1 vol4 iv1 p4 #de4 ,,beijerinck1 ,m4 ,w43 #aiae1 ,die ,leuchtbacterien der ,nordsee im ,august und ,september4 ,folia microbiologica1 iv4 ,,blanchetiere3 #aiac1 ,oxydation et ,luminescence4 ,c4 ,r4 ,ac4 ,sc41 clvii1 #aah4 ,,bongardt1 ,j43 #aijc1 ,beitraege zur ,kenntnis der ,leuchtorgane einheimischer ,lampyriden4 ,ztsch4 f4 wiss4 ,zool41 ,bd4 #ge1 pp4 #a to #de4 ,,boyle1 ,r43 #affg1 ,philo4 ,trans4 ,abridged ,roy4 ,soc41 #eth ,ed41 vol4 ii 7#agbb71 p4 #bjf1 and iii 7#agdi71 p4 #fdf4 ,,brauer1 ,a43 #aijd1 ,ueber die ,knochenfische4 ,verhandl4 ,deutsch4 ,zool4 ,ges41 vol4 xiv1 pp4 #af-ce4 ,,brauer1 ,a43 #aijf1 ,die ,tiefseefische4 ,i4 ,systematischer ,teil4 ,,ii4 ,anatomischer ,teil4 ,wiss4 ,ergeb4 der ,valdivia-,exped4 ,jena4 ,,carradori1 ,b43 #agih1 ,experiments and ,observations on the ,phosphorescence of the ,luciole1 ,lampyris italica4 ,ann4 d4 ,chemie1 xxiv1 pp4 #if-aja2 ,philos4 ,magazine1 ii1 pp4 #gg-hj4 ,,carus3 #ahfd1 ,experiences sur la matiere phosphorescente de la ,lampyris italica et action d'eau pour rendre a la matiere dessechee cette phosphorescence4 ,c4 ,r4 ,ac4 ,sc41 lix1 pp4 #fjg-fjh4 ,,centnerszwer1 ,m43 #ahih1 ,ueber den ,katalytischen ,einfluss verscheidener ,gase und ,daempfe auf die ,oxydation des ,phosphors4 ,z4 ,physik4 ,chem41 #bf1 pp4 #a-df4 ,,chun1 ,c43 #ahic1 ,leuchtorgan und ,facettenauge4 ,ein ,beitrag zur ,theorie des ,sehens in grossen ,meerstiefen4 ,biol4 ,ctbl41 ,bd4 xiii1 pp4 #edd-ega4 ,,chun1 ,c43 #ahif1 ,atlantis4 ,biologische ,studien ueber pelagische ,organismen1 ,chap4 ,,vi4 ,die ,leuchtorgane der ,euphausiden4 ,biblioth4 ,zool41 vol4 vii1 ,h4 #ai1 pp4 #aif-bab4 ,,chun1 ,c43 #aijc1 ,ueber ,leuchtorgane und ,augen von ,tiefsee-,cephalopoden4 ,verhandl4 ,dtsch4 ,zool4 ,ges41 pp4 #fg-ia4 ,,coblentz1 ,w4 ,w43 #aiji1 ,notiz ueber eine der ,feuerfliege herruehrende fluorenzierende ,substanz4 ,physik ,zeit41 x1 pp4 #iee-ief4 ,,coblentz1 ,w4 ,w43 #aiab1 ,a ,physical ,study of the ,firefly4 ,publication ,no4 #afd1 ,carnegie ,inst41 ,wash41 ,d4,c4 ,,coblentz1 ,w4 ,w41 and ,,emerson1 ,w4 ,b43 #aiag1 ,relative ,sensibility of the ,average ,eye to ,light of ,different ,colors and ,some ,practical ,applications to ,radiation ,problems4 ,bur4 ,standards1 ,scient4 ,pap4 ,no4 #cjc4 ,,conroy1 ,j43 #ahhb1 ,the ,spectrum of the ,light ,emitted by the ,glowworm4 ,nature1 vol4 xxvi1 p4 #cai4 ,,delepine1 ,w4 ,l43 #aiaj1 ,sur quelques composes organiques spontanement oxydables avec phosphorescence4 ,c4 ,r4 ,ac4 ,sc41 vol4 cl1 pp4 #hgf-hgh4 ,,dubois1 ,r43 #ahhe1 ,fonction photogenique des ,pyrophores4 ,c4 ,r4 ,soc4 ,biol41 vol4 xxxvii1 #eei-efb4 ,,dubois1 ,r43 #ahhf1 ,les ,elaterides ,lumineux4 ,bull4 ,soc4 ,zool4 de ,france1 vol4 xi1 pp4 #a-bge4 ,,dubois1 ,r43 #ahhg;a1 ,de la fonction photogenique chez le ,pholas dactylus4 ,c4 ,r4 ,ac4 ,sc41 vol4 cv1 p4 #fij4 ,,dubois1 ,r43 #ahhg;b1 ,note sur la ,fonction ,photogenique chez les ,pholades4 ,c4 ,r4 ,soc4 ,biol41 pp4 #efd-efg4 ,,dubois1 ,r43 #ahib1 ,anatomie et ,physiologie ,comparees de la ,pholade ,dactyle4 ,ann4 d4 ,univ4 ,lyon1 vol4 ii1 p4 #a-aee4 ,,dubois1 ,r43 #ahic1 ,sur le mecanisme de production de la lumiere chez ,orya barbarica d',algerie4 ,c4 ,r4 ,ac4 ,sc41 ,paris1 ,july #agth4 ,,dubois1 ,r43 #ahif1 ,nouvelles ,recherches sur la ,production de la ,lumiere par les etres vivants4 ,c4 ,r4 ,soc4 ,biol41 vol4 xlviii1 p4 #iie4 ,,dubois1 ,r43 #aija;a1 ,nouvelles recherches sur la ,biophotogenese4 ,c4 ,r4 ,soc4 ,biol41 vol4 liii1 p4 #gjb4 ,,dubois1 ,r43 #aija;b1 ,luminescence obtenue par certains procedes organiques4 ,c4 ,r4 ,ac4 ,sc41 vol4 cxxxii1 p4 #dca4 ,,dubois1 ,r43 #aijg1 ,mecanisme ,intime de la ,formation de la ,luciferine2 analogies et homologies des organs de ,poli et la glande hypobranchiale des ,molluscs ,purpurigenes4 ,c4 ,r4 ,soc4 ,biol41 vol4 lxii1 p4 #hej4 ,,dubois1 ,r43 #aiac1 ,mecanisme ,intime de la ,production de la lumiere chez les ,organismes ,vivants4 ,ann4 ,soc4 ,linn4 de ,lyons1 vol4 lx1 pp4 #ha-ig4 ,,dubois1 ,r43 #aiad;a1 ,de la ,place ,occupee par la ,biophotogenese dans la ,series des ,phenomenes ,lumineux4 ,ann4 ,soc4 ,linn4 de ,lyons1 vol4 lxi1 pp4 #bdg-bef4 ,,dubois1 ,r43 #aiad;b1 ,examen ,critique de la ,question de la ,biophotogenese4 ,ann4 ,soc4 ,linn4 de ,lyons1 vol4 lxi1 pp4 #beg-bfe4 ,,dubois1 ,r43 #aiaf1 ,sur l',anatomie de la glande ,photogene de ,pholas dactylus4 ,ann4 ,soc4 ,linn4 de ,lyons1 vol4 lxiii1 pp4 #i-ac4 ,,dubois1 ,r43 #aiag;a1 ,a propos de ,quelques ,recherches ,recentes de ,m4 ,newton ,harvey sur la ,biophotogenese et du ,role ,important de la ,preluciferine4 ,c4 ,r4 ,soc4 ,biol41 ,december #bb;d4 ,,dubois1 ,r43 #aiag;b1 ,etude ,critique de ,quelques ,travaux ,resents ,relatif a la ,biophotogenese4 ,ann4 ,soc4 ,linn4 de ,lyons1 vol4 lxiv1 pp4 #fe-aah4 ,,dubois1 ,r43 #aiah;a1 ,sur la ,synthese de la ,luciferine4 ,c4 ,r4 ,ac4 ,sc41 vol4 clxvi1 p4 #egh4 ,,dubois1 ,r43 #aiah;b1 ,nouvelles ,recherches sur la ,biophotogenese4 ,synthese ,naturelle de la ,luciferine4 ,c4 ,r4 ,soc4 ,biol41 vol4 lxxxi1 p4 #cag4 ,,dubois1 ,r43 #aiah;c1 ,sur la ,lumiere ,physiologique 7,nouvelle reponse a ,m4 ,newton ,harvey74 ,c4 ,r4 ,soc4 de ,biol41 vol4 lxxxi1 p4 #dhd4 ,,dubois1 ,r43 #aiai;a1 b1 ,symbiotes1 ,vacuolides1 ,mitrochondries et ,leucites4 ,c4 ,r4 ,soc4 ,biol41 vol4 lxxxii1 ,may #ajth and ,july #bfth4 ,,dubois1 ,r43 #aiai;c1 ,reversibilite de la fonction photogenique par l'hydrogenase de la pholade dactyle4 ,c4 ,r4 ,soc4 ,biol41 vol4 lxxxii1 p4 #hdj4 ,,dubois1 ,r41 et ,,regard1 ,p43 #ahhd1 ,note sur l'action des hautes pressions sur la fonction photogenique du ,lampyre4 ,c4 ,r4 ,soc4 ,biol41 vol4 xxxvi1 pp4 #fge-fgf4 ,,ehrenberg1 ,c4 ,g43 #ahca1 ,ueber einen neuen1 das ,leucten der ,ostsee bedingenden1 lebenden ,koerper4 ,poggendorffs ,ann4 d4 ,phys4 und ,chem41 ,bd41 vol4 xxiii1 p4 #adg4 ,,ehrenberg1 ,c4 ,g43 #ahcd1 ,das ,leuchten des ,meers4 ,abhandl4 d4 ,kgl4 ,akad4 d4 ,wiss4 ,berlin1 pp4 #daa-egb4 ,,ehrenberg1 ,c4 ,g43 #ahei1 ,ueber das ,leuchten und ueber neue microskopische ,leuchthiere des ,mittelmeeres4 ,monatsber4 d4 ,berliner ,akad41 pp4 #gbg-gia4 ,,eijkman1 ,c43 #ahib1 ,geneeskundig ,tidschrift v4 ,ned4 ,ind41 ,deel1 #cb ,abl4 #d1 p4 #aji4 ,,eliot1 ,c43 #aijg-aiae1 ,notes on a ,collection of ,nudibranchs from the ,red ,sea4 ,journ4 ,linn4 ,soc4 ,london1 vol4 xxxi1 p4 #ajb4 ,,emery1 ,c43 #ahhd1 ,untersuchungen ueber ,luciola italica ,l4 ,ztschr4 f4 ,wiss4 ,zool41 ,bd4 xl1 pp4 #cch-cee4 ,,emmerling1 ,o43 #aiji1 ,hydrolyse der ,meerleuchtinfusorien der ,nordsee 7,noctiluca miliaris74 ,biochem4 ,zt41 vol4 xviii1 pp4 #cgb-cgd4 ,,enders1 ,h4 ,e43 #aiji1 ,a ,study of the ,life ,history and ,habits of ,chaetopterus variopedatus1 ,renier et ,claparede4 ,journ4 ,morph41 vol4 xx1 pp4 #dgi-ecb4 ,,ewan1 ,t43 #ahie1 ,ueber die ,oxydationsgeschwindigkeit von ,phosphor1 ,schweifel und ,aldehyde4 ,zeit4 physik4 ,chem41 vol4 xvi1 pp4 #cae-cdc4 ,,exner1 ,s43 #aijc1 ,einige ,beobachtungen ueber die durch ,radiumstrahlen in den tierischen ,geweben erzeugte ,phosphoreszenz4 ,ctbl4 f4 ,physiol41 ,bd4 xvii1 pp4 #agg-agi4 ,,fabre1 ,j4 ,h43 #ahee1 ,recherches sur la ,cause de la ,phosphorescence d',agaric de ,l',olivier4 ,ann4 d4 ,sc4 ,nat41 #d ser41 vol4 iv1 p4 #agi4 ,,fahrig1 ,e43 #ahij1 ,the ,phosphorescence ,produced ,upon the ,first ,contact of ,ozone with ,certain ,fluids4 ,chem4 ,news1 vol4 lxii1 pp4 #ci-dj4 ,,falger1 ,f43 #aijh1 ,untersuchungen ueber das ,leuchten von ,acholoe astericola4 ,biol4 ,ctbl41 ,bd4 xxviii1 pp4 #fda-fdi4 ,,fischer1 ,b43 #ahhh;a1 ,ueber einen neuen lichtentwickelenden ,spaltpilz4 ,ctbl4 f4 ,bakt41 ,bd4 iii1 pp4 #aje and #acg4 ,,fischer1 ,b43 #ahhh;b1 ,bacterium ,wachstum bei #j deg44 ,ctbl4 f4 ,bakt41 ,bd4 iv1 p4 #hi4 ,f,oe,r,s,t,e,r1 ,j43 #ahhg1 ,ueber einige ,eigenschaften leuchtender ,bakterien4 ,ctbl4 f4 ,bakt41 ,bd4 ii1 p4 #cci4 ,f,oe,r,s,t,e,r1 ,j43 #ahib1 ,ueber die ,entwicklung von ,bakterien bei niederer ,temperatur4 ,centralbl4 f4 ,bak41 vol4 xii1 pp4 #dca-dcf4 ,f,oe,r,s,t,e,r1 ,j43 #aiad1 ,ueber die ,leuctorgane und das ,nervensystem von ,pholas dactylus4 ,zeit4 f4 wiss4 ,zool41 vol4 cix1 pp4 #cdi-cic4 ,,forsyth1 ,r4 ,w43 #aiaj1 ,the ,spectrum of ,bacterial ,luminosity4 ,nature1 vol4 lxxxiii1 p4 #g4 ,,frankland1 ,p43 #ahih1 ,the ,action of ,bacteria on the ,photographic ,plate4 ,ctbl4 f4 ,bakt41 #ast ,abt4 ,bd4 xxiv1 pp4 #fji-fab4 ,,friedberger1 ,e41 and ,,doepner1 ,h43 #aijg1 ,ueber den ,einfluss von ,schimmelpilzen auf die ,lichtintensitaet in ,leuchtbacterienkulturen1 etc4 ,centralbl4 f4 ,bakt41 #ast ,abt41 xliii1 p4 #a4 ,,friend1 ,h43 #ahic1 ,luminous ,earthworm4 ,nature1 vol4 xlvii1 p4 #dfb4 ,,fuchs1 ,s43 #ahia1 ,einige ,versuche an der ,leuchtorganen von ,elater noctilucus4 ,centralbl4 f4 ,physiol41 vol4 v1 pp4 #cba-cbe4 ,,galloway and ,,welch3 #aiaa1 ,studies on a ,phosphorescent ,bermudan ,annelid1 ,odontosyllis enopla1 ,verrell4 ,trans4 ,amer4 ,micros4 ,soc41 vol4 xxx1 pp4 #ac-ci4 ,,geipel1 ,e43 #aiae1 ,beitraege zur ,anatomie der ,leuchtorgane tropischer ,kaefer4 ,zeit4 ,wiss4 ,zool41 vol4 cxii1 pp4 #bci-bij4 ,,gernez1 ,d43 #aije1 ,triboluminescence des composes ,metalliques4 ,c4 ,r4 ,ac4 ,sc41 vol4 cxl1 pp4 #aacd1 #abcd1 #accg4 ,,giard1 ,a43 #ahij1 ,nouvelles recherches sur les bacteries lumineuses pathogenes4 ,comp4 rend4 soc4 ,biol41 ,t4 xlii1 pp4 #ahh-aia4 ,,giard1 ,a41 and ,,billet1 ,a43 #ahhi1 ,observations sur la ,maladie phosphorescente des ,talitres et ,autres ,crustaces4 ,compt4 rend4 soc4 ,biol41 vol4 #a1 ,ser4 #i1 p4 #eic4 ,,gibson1 ,k4 ,s41 and ,,mcnicholas1 ,h4 ,j43 #aiai1 ,the ,ultra-,violet and ,visible ,transmission of ,eye-protective ,glasses4 ,bureau of ,standards4 ,tech4 ,papers ,no4 #aai4 ,,giesbrecht1 ,w43 #ahie1 ,ueber das ,leuchten der pelagischen ,copepoden und das tierische ,leuchten im allgemeinen4 ,mitteil4 d4 ,zool4 ,st4 ,neapel1 ,bd4 xi1 pp4 #fdh-fid4 ,,giesbrecht1 ,w43 #ahif1 ,ueber den ,stiz der ,lichtentwicklung in den ,photosphaerien der ,euphausiiden4 ,zool4 ,anz41 ,bd4 xix1 pp4 #dhf-dij4 ,,goss1 ,b4 ,c43 #aiag1 ,light ,production at ,low ,temperatures by ,catalysis with ,metal and ,metallic ,oxide ,hydrosols4 ,journ4 ,biol4 ,chem41 vol4 xxxi1 pp4 #bga-bgi4 ,,greef1 ,r43 #ahhb1 ,ueber die rosettenfoermigen ,leuchtorgane der ,tomopteriden und zwei neue ,arten von ,tomopteris4 ,zool4 ,anz41 ,bd4 v1 pp4 #chd-chg4 ,,greene1 ,c4 ,w43 #ahii1 ,the ,phosphorescent ,organs in the ,toad ,fish1 ,porichthys natatus1 ,girard4 ,jour4 of ,morph41 vol4 xv1 pp4 #ffg-fhd4 ,,guinchant3 #aije1 ,sur la triboluminescence de l'acide arsenieux4 ,c4 ,r4 ,ac4 ,sc41 vol4 cxl1 p4 #aagj4 ,,handrick1 ,k43 #aija1 ,zur ,kenntnis des ,nervensystems und der ,leuchtorgane von ,argyropelecus hemigymnus4 ,zoologica1 ,bd4 xiii1 ,heft4 #cb1 pp4 #a-fh4 ,,hankel1 ,w43 #ahfb1 ,notiz ueber ,phosphorisches ,leuchten des ,fleisches4 ,ann4 d4 ,phys4 u4 ,chem41 ,bd4 cxv1 p4 #fb4 ,,hansen1 ,h4 ,j43 #aijc1 ,on the ,crustaceans of the ,genera ,petalidium and ,sergestes from the ,challenger1 with an ,account of ,luminous ,organs in ,sergestes challengeri n4 ,sp4 ,proc4 ,zool4 ,soc41 ,london1 #aijc1 vol4 i1 pp4 #eb-gg4 ,,harvey1 ,e4 ,b43 #aiag1 ,a ,physiological ,study of ,specific ,gravity and ,luminescence in ,noctiluca1 with ,special ,reference to ,anaesthesia4 ,pub4 ,no4 #bea1 ,carneg4 ,inst41 ,wash41 pp4 #bce-bec4 ,,harvey1 ,e4 ,n43 #aiac1 ,the ,temperature ,limits of ,phosphorescence of ,luminous ,bacteria4 ,biol4 ,bull41 vol4 ii1 pp4 #def-deg4 ,,harvey1 ,e4 ,n43 #aiad1 ,on the ,chemical ,nature of the ,luminous ,material of the ,firefly4 ,,science ,n4 ,s41 vol4 xl1 pp4 #cc-cd4 ,,harvey1 ,e4 ,n43 #aiae;a1 ,experiments on the ,nature of the ,photogenic ,substance in the ,firefly4 ,jour4 ,am4 ,chem4 ,soc41 vol4 xxxvii1 pp4 #cif-dja4 ,,harvey1 ,e4 ,n43 #aiae;b1 ,studies on ,light ,production by ,luminous ,bacteria4 ,am4 ,jour4 ,physiol41 vol4 xxxvii1 pp4 #bcj-bdj4 ,,harvey1 ,e4 ,n43 #aiae;c1 ,the ,effect of ,certain ,organic and ,inorganic ,substances ,upon ,light ,production by ,luminous ,bacteria4 ,biol4 ,bull41 vol4 xxix1 pp4 #cjh-cab4 ,,harvey1 ,e4 ,n43 #aiaf;a1 ,the ,mechanism of ,light ,production in ,animals4 ,science ,n4 ,s41 vol4 xliv1 pp4 #bjh-bji4 ,,harvey1 ,e4 ,n43 #aiaf;b1 ,studies on ,bioluminescence4 ,,ii4 ,on the ,presence of ,luciferin in ,luminous ,bacteria4 ,am4 ,jour4 ,physiol41 vol4 xli1 pp4 #ddi-ded4 ,,harvey1 ,e4 ,n43 #aiaf;c1 ,studies in ,bioluminescence4 ,,iii4 ,on the ,production of ,light by ,certain ,substances in the ,presence of ,oxidases4 ,am4 ,jour4 ,physiol41 vol4 xli1 pp4 #ded-dfd4 ,,harvey1 ,e4 ,n43 #aiaf;d1 ,the ,light-producing ,substances1 ,photogenin and ,photophelein of ,luminous ,animals4 ,science ,n4 ,s41 vol4 xliv1 pp4 #feb-fed4 ,,harvey1 ,e4 ,n43 #aiag;a1 ,studies on ,bioluminescence4 ,,iv4 ,the ,chemistry of ,light ,production in a ,japanese ,ostracod ,crustacean ,cypridina hilgendorfii1 ,muller4 ,amer4 ,jour4 ,physiol41 vol4 xlii1 pp4 #cah-cda4 ,,harvey1 ,e4 ,n43 #aiag;b1 ,v4 ,the ,chemistry of ,light ,production by the ,firefly1 ,id41 pp4 #cdb-cdh4 ,,harvey1 ,e4 ,n43 #aiag;c1 ,,vi4 ,the ,light ,production in a ,japanese ,pennatulid1 ,cavernularia haberi1 ,id41 pp4 #cdi-ceh4 ,,harvey1 ,e4 ,n43 #aiag;d1 ,what ,substance is the ,source of ,light in the ,firefly8 ,science ,n4 ,s41 vol4 xliv1 pp4 #bda-bdc4 ,,harvey1 ,e4 ,n43 #aiag;e1 ,studies on ,bioluminescence4 ,,viii4 ,the ,mechanism of the ,production of ,light during ,oxidation of ,pyrogallol4 ,jour4 ,biol4 ,chem41 vol4 xxxi1 pp4 #caa-ccf4 ,,harvey1 ,e4 ,n43 #aiah1 ,studies on ,bioluminescence4 ,,vii4 ,reversibility of the ,photogenic ,reaction in ,cypridina4 ,jour4 ,gen4 ,physiol41 vol4 i1 pp4 #acc-ade4 ,,harvey1 ,e4 ,n43 #aiai;a1 ,studies on ,bioluminescence4 ,,ix4 ,chemical ,nature of ,cypridina ,luciferin and ,cypridina ,luciferase4 ,jour4 ,gen4 ,physiol41 vol4 i1 pp4 #bfi-bic4 ,,harvey1 ,e4 ,n43 #aiai;b1 ,studies on ,bioluminescence4 ,x4 ,carbon ,dioxide ,production during ,luminescence of ,cypridina ,luciferin4 ,jour4 ,gen4 ,physiol41 vol4 ii1 pp4 #acc-ace4 ,,harvey1 ,e4 ,n43 #aiai;c1 ,,xi4 ,heat ,production during ,luminescence of ,cypridina ,luciferin4 ,id41 vol4 ii1 pp4 #acg-adc4 ,,harvey1 ,e4 ,n43 #aibj1 ,studies on ,bioluminescence1 ,,xii4 ,id41 ii1 #bjg-bac4 ,,heinemann1 ,c43 #ahgb1 ,untersuchungen ueber die ,leuchtorgane der bei ,vera-,cruz vorkommenden ,leuchtkaefer4 ,arch4 f4 mikr4 ,anat41 ,bd4 viii1 pp4 #dfa-dga4 ,,heinemann1 ,c43 #ahgc1 ,aschenanalyse von ,leuchtorganen mexikanischer ,cucujos4 ,pflueger's ,arch41 ,bd4 vii1 pp4 #cfe-cfg4 ,,heinemann1 ,c43 #ahhf1 ,zur ,anatomie und ,physiologie der ,leuchtorgane mexikanischer ,cucujos4 ,archiv f4 ,mikr4 ,anat41 ,bd4 xxvii1 pp4 #bif-chb4 ,,heller1 ,j4 ,,florian3 #ahec u4 #ahed1 ,ueber das ,leuchten im ,pflanzen-und ,tierreiche4 ,arch4 f4 ,physiol4 u4 ,pathol4 ,chem4 u4 ,mikrosk41 mit bes4 ,ruecksicht auf med4 ,diagnost4 u4 ,therapie ,wien41 ,n4 ,f41 ,bd4 vi1 pp4 #dd1 #ha1 #aba1 #afa1 #bja1 #bda4 ,,henneberg1 ,w43 #ahii1 ,leuchtbacterien als ,krankheitserreger bei ,schwammuecken4 ,centralbl4 f4 ,bakt41 #ast ,abt4 xxv1 pp4 #fdi-fej4 ,,hoyle1 ,w4 ,f43 #aijb1 ,the ,luminous ,organs of ,ptergioteuthis margaritifera1 ,mediterranean ,cephalopod4 ,manchester ,mem41 vol4 xlvi1 ,no4 #af4 ,,hulme1 ,n43 #ahjj1 ,experiments and ,observations on the ,light ,which is ,spontaneously ,emitted with ,some ,degree of ,permanency from ,various ,bodies4 ,phil4 ,trans4 ,roy4 ,soc41 pp4 #afa-ahg4 ,,hyde1 ,e4 ,p41 ,,forsyth1 ,w4 ,e4 and ,,cady1 ,f4 ,e43 #aiah1 ,the ,visibility of ,radiation4 ,astrophys4 ,journ41 vol4 xlviii1 pp4 #fe-hh4 ,,hyde1 ,e4 ,p41 ,,forsyth1 ,w4 ,e41 and ,,cady1 ,f4 ,e43 #aiai1 ,a ,new ,experimental ,determination of the ,brightness of a ,black ,body and of the ,mechanical ,equivalent of ,light4 ,physical ,review1 vol4 xii1 pp4 #de-eh4 ,,ishikawa1 ,c43 #aiac1 ,einige ,bemerkungen ueber den leuchtenden ,tintenfisch1 ,watasenia ,nov4 ,gen4 7,abraliopsis der ,autoren7 scintillans1 ,berry1 aus ,japan4 ,zool4 ,anz41 #aiac1 vol4 xliii1 pp4 #afb-agb4 ,,issatschenko1 ,b43 #aijc1 ,quelques experiences avec la lumiere bacterienne4 ,ctbl4 f4 ,bakt41 ,abt4 #b1 ,bd4 x1 pp4 #dig-dii4 ,,issatschenko1 ,b43 #aijg1 ,zur ,erforschung des ,bakterienlichtes4 ,centralb4 f4 ,bakt41 ,bd4 xix1 pp4 #aaf-aag4 ,,issatschenko1 ,b43 #aiaa1 ,erforschung des bakterielle ,leuchten des ,chironomus 7,diptera74 ,bull4 d4 jard4 imp4 botan4 ,st4 ,petersburg1 vol4 xi1 p4 #db4 ,,ives1 ,h4 ,e43 #aiaj1 ,further ,studies of the ,firefly4 ,physical ,rev41 vol4 xxxi1 pp4 #fcg-fea4 ,,ives1 ,h4 ,e43 #aiae1 ,the ,total ,luminous ,efficiencies of ,present-day ,illuminants4 ,physical ,rev41 ,ser4 #b1 vol4 v1 p4 #cij4 ,,ives1 ,h4 ,e41 and ,,coblentz1 ,w4 ,w43 #aiaj1 ,luminous ,efficiency of the ,firefly4 ,bull4 ,bur4 ,stand41 ,wash41 ,d4 ,c41 vol4 vi1 pp4 #cba-ccf4 ,,ives1 ,h4 ,e41 and ,,luckiesh1 ,m43 #aiaa1 ,the ,effect of ,red and ,infra-red on the ,decay of ,phosphorescence in ,zinc ,sulphide4 ,astrophys4 ,journ41 vol4 xxxiv1 pp4 #agc-aif4 ,,johann1 ,l43 #ahii1 ,ueber eigentuemliche epitheliale ,gebilde 7,leuchtorgane7 bei ,spinax niger4 ,ztschr4 f4 wiss ,zool41 ,bd4 lxvi1 pp4 #acf-afj4 ,,joubin1 ,l43 ,note sur l'appareil photogene d'un cephalopode 7,histioteuthis ,rupelii74 ,compt4 rend4 soc4 ,biol41 #ahic1 pp4 #adb-adf4 ,,jourdan1 ,,et43 #ahhe1 ,structure des elytres de quelques ,polynoes4 ,zool4 ,anz41 ,bd4 viii1 pp4 #abh-acd4 ,,jourdan1 ,,et43 #ahhg1 ,structure histologique des teguments et des appendices sensitifs de l',hermione hysterix et du ,polynoe ,grubiana4 ,arch4 ,zool4 ,exper41 #ahhg1 #bnd ser41 ,t4 v1 pp4 #ia-abb4 ,,jousset1 ,,de ,,bellesme3 #ahhj1 ,recherches experimentales sur la phosphorescence du lampyre4 ,jour4 de l'anat4 et de la ,physiol41 ,t4 xvi1 pp4 #aba-afi4 ,,kastle1 ,j4 ,h41 and ,,mcdermott1 ,f4 ,a43 #aiaj1 ,some ,observations on the ,production of ,light by the ,firefly4 ,amer4 ,jour4 ,physiol41 vol4 xxvii1 pp4 #abb-aea4 ,,katz1 ,o43 #ahia1 ,zur ,kenntnis der ,leuchtbakterien4 ,centralb4 f4 ,bak41 pp4 #i1 #aeg1 #aii1 #bbi1 #beh1 #caa1 #cdc4 ,,kemp1 ,s43 #aiaj1 ,notes on the ,photophores of ,decapod ,crustacea4 ,proc4 ,zool4 ,soc41 ,london1 pp4 #fci-fea4 ,,knab1 ,f43 #aiji1 ,luminous ,termite ,hills4 ,science1 vol4 xxx1 pp4 #egd-ege4 ,k,oe,l,l,i,k,e,r1 ,a4 ,v43 #aheh1 ,ueber die ,leuchtorgane von ,lampyriden4 ,verh4 d4 ,phys4 ,med4 ,ges41 ,wuerzburg1 ,bd4 viii1 pp4 #bag-bbd4 ,k,oe,l,l,i,k,e,r1 ,a4 ,v43 #ahei1 ,ueber die ,leuchtorgane der amerikanischen ,pyrophorus-,arten4 ,verh4 d4 ,phys4 ,med4 ,ges41 ,stiz4 ber41 ,wuerzburg1 ,bd4 ix1 p4 #bh4 ,,krunkenberg1 ,f4 ,c4 ,w43 #ahhg1 ,neue ,tatsachen fuer eine vergleichende ,physiologie der ,phosphorescenzerscheinungen bei ,tieren und bei ,pflanzen4 ,vergl4 ,physiol4 ,studien1 ,heidelberg1 ,,ii ,reihe1 #dth ,abt41 pp4 #gg-adb4 ,,kutscher1 ,f43 #ahig1 ,zur ,physiologie der ,phosphorescenz4 ,ztschr4 f4 ,physiol4 ,chem41 #ahig1 ,bd4 xxiii1 pp4 #aji-aac4 ,,kutscher1 ,f43 #aiji1 ,die ,leuchtorgane von ,archoloe astericola4 ,ztschr4 f4 wiss4 ,zool41 ,bd4 xcii1 pp4 #ge-ajb4 ,,langley1 ,s4 ,p41 and ,,very1 ,f4 ,w43 #ahij1 ,on the ,cheapest ,form of ,light from ,studies at the ,allegheny ,observatory4 ,amer4 ,jour4 of ,sc41 #crd series1 vol4 xl1 p4 #ig4 ,also ,smiths4 ,miscell4 ,coll41 xli1 #aija4 ,,langley1 ,s4 ,p43 #aijb1 ,ann4 ,astrophys4 ,obs41 vol4 ii1 p4 #e4 ,,lankester1 ,e4 ,,ray3 #ahfg1 ,preliminary ,notice of ,some ,observations with the ,spectroscope on ,animal ,substances4 ,jour4 of ,anat4 and ,physiol41 vol4 ii1 p4 #aaf4 ,,lehmann1 ,k4 ,b43 #ahhi1 ,studien ueber ,bacterium phosphorescens1 ,fischer4 ,ctbl4 f4 ,bakt41 ,bd4 v1 p4 #ghe4 ,,lenard1 ,p41 and ,,wolf1 ,m43 #ahhh1 ,lumineszenz der ,pyrogallussauere4 ,ann4 ,phys4 u4 ,chem41 #ahhh1 ,n4 ,f4 xxxiv1 pp4 #iah-ibe4 ,,lendenfeld1 ,r43 #ahhg1 ,die ,leuchtorgane der ,fische4 ,biol4 ,ctbl41 ,bd4 vii1 pp4 #fji-fba4 ,,linnemann1 ,e43 #aheh1 ,phosphorescenz des ,kaliums und ,natriums4 ,j4 f4 ,prac4 ,chem41 vol4 lxxv1 p4 #abh4 ,,lode1 ,a43 #aijd1 ,versuche1 die optische ,lichtintensitaet bei ,leuchtbakterien zu bestimmen4 ,ctbl4 f4 ,bakt41 ,i ,abt41 ,orig41 ,bd4 xxxv1 pp4 #ebd-ebg4 ,,lode1 ,a43 #aijh1 ,experimente mit ,leuchtbakterien4 ,referate4 ,centralb4 f4 ,bakt41 #bnd ,abt41 vol4 xxii1 p4 #dba4 ,,ludwig1 ,f43 #ahgd1 ,ueber die ,phosphorescenz der ,pilze und des ,holzes4 ,diss4 ,goettingen1 #cj pages4 ,,ludwig1 ,f43 #ahhd1 ,ueber die ,spektroskopische ,untersuchung photogener ,pilze4 ,zeit4 wiss4 ,mikr41 vol4 i1 pp4 #aha-aij4 ,,ludwig1 ,f43 #ahhg1 ,die bisherigen ,untersuchungen ueber photogene ,bakterien4 ,centralb4 f4 ,bakt41 vol4 ii1 pp4 #cgb and #dja4 ,,ludwig1 ,f43 #aija1 ,phosphorezierende ,tausendfuessler und die ,lichtfaeule des ,holzes4 ,centralb4 f4 ,bakt41 ,abt4 ,,ii41 ,bd4 vii1 pp4 #bgj-bgd4 ,,lund1 ,e4 ,j43 #aiaa1 ,on the ,structure1 ,physiology and ,use of ,photogenic ,organs1 with ,special ,reference to the ,lampyridae4 ,journ4 ,exp4 ,zool41 vol4 xi1 pp4 #dae-dfg4 ,,macaire1 ,j43 #ahba1 ,memoire sur la phosphorescence des ,lampyres4 ,ann4 d4 ,chimie et ,phy41 ,t4 xvii1 pp4 #aea-afg4 ,,macaire1 ,j43 #ahbb1 ,ueber die ,phosphorescenz der ,leuchtkaefer4 ,gilbert's ,annal4 d4 ,physik41 ,t4 lxx1 pp4 #bfe-bhj4 ,,macaire1 ,j43 #ahbb1 ,on the ,phosphorescence of ,luminous ,insects4 ,quarterly ,journ4 ,science1 ,lit4 and ,art1 vol4 xii1 pp4 #aha-ahb4 ,,macartney1 ,j43 #ahaj1 ,observations on ,luminous ,animals4 ,philos4 ,transact41 vol4 c1 pp4 #beh-bic4 ,,macfadyen1 ,a43 #aijj1 ,on the ,influence of the ,temperature of ,liquid ,air on ,bacteria4 ,proc4 ,roy4 ,soc41 ,london1 vol4 lxvi1 p4 #ahj4 ,,macfadyen1 ,a43 #aijb1 ,on the ,influence of the ,prolonged ,action of ,liquid ,air on ,micro-organisms and the ,effect of ,mechanical ,trituration at the ,temperatures of ,liquid ,air on ,photogenic ,bacteria4 ,proc4 ,roy4 ,soc41 vol4 lxxi1 p4 #gf4 ,,mace3 #ahhg1 ,les glandes preanales et la phosphorescence des geophiles4 ,comp4 rend4 soc4 ,biol41 pp4 #cg-ci4 ,,mangold1 ,e43 #aijg;a1 ,ueber das ,leuchten der ,tiefseefische4 ,pflueger's ,arch41 ,bd4 cxix1 pp4 #ehc-fja4 ,,mangold1 ,e43 #aijg;b1 ,leuchtende ,schlangensterne und die ,flimmerbewegung bei ,ophiopsila4 ,pflueger's ,arch41 ,bd4 cxviii1 pp4 #fac-fdj4 ,,massart1 ,j43 #ahic1 ,sur l'irritabilite des ,noctiluques4 ,bull4 scientifique de la ,france et de la ,belgique1 ,t4 #be4 ,,mast1 ,s4 ,o43 #aiab1 ,behavior of ,fireflies 7,photinus ardens871 with ,special ,reference to the ,problem of ,orientation4 ,jour4 ,animal ,behavior1 vol4 ii1 pp4 #bef-bgb2 also ,science1 vol4 xxxv1 p4 #dfj4 ,,matteuci1 ,c43 #ahdc1 ,sur la phosphorescence du lampyre d',italie 7,l4 italica74 ,c4 ,r4 ,ac4 ,sc41 vol4 xvii1 pp4 #cji-cab4 ,,mcdermott1 ,f4 ,a43 #aiaj-aiag1 ,observations on the ,light ,emission of ,american ,lampyridae4 ,canad4 ,entomol41 #aiaj1 vol4 xlii1 pp4 #ceg-cfc2 #aiaa1 vol4 xliii1 pp4 #cii-djf2 #aiab1 vol4 xliv1 p4 #gc2 #aiab1 vol4 xliv1 p4 #cji2 #aiag1 vol4 xlix1 pp4 #ec-fa4 ,,mcdermott1 ,f4 ,a43 #aiaa;a1 ,luciferesceine1 the ,fluorescent ,material ,present in ,certain ,luminous ,insects4 ,jour4 ,amer4 ,chem4 ,soc41 vol4 xxxiii1 pp4 #daj-daf4 ,,mcdermott1 ,f4 ,a43 #aiaa;b1 ,the ,stability of the ,photogenic ,material of the ,lampyridae and ,its ,probable ,chemical ,nature4 ,journ4 ,amer4 ,chem4 ,soc41 vol4 xxxiii1 pp4 #agia-agif4 ,,mcdermott1 ,f4 ,a4 and ,,crane1 ,c4 ,g43 #aiaa;c1 ,a ,comparative ,study of the ,structure of the ,photogenic ,organs of ,certain ,american ,lampyridae4 ,amer4 ,nat41 vol4 xlv1 pp4 #cjf-cac4 ,,mcdermott1 ,f4 ,a43 #aiaa;d1 ,some ,observations on a ,photogenic ,microorganism1 ,pseudomonas ,lucifera1 ,molish4 ,proc4 ,biol4 ,soc41 ,wash41 vol4 xxiv1 pp4 #agi-ahd4 ,,mcdermott1 ,f4 ,a43 #aiaa;e1 ,recent ,advances in ,our ,knowledge of the ,production of ,light in ,living ,organisms4 ,smithsonian ,rep41 pp4 #cde-cfb2 also ,sci4 ,amer4 ,suppl41 ,no4 #ahdb1 pp4 #bej-bea4 ,,mcdermott1 ,f4 ,a43 #aiac1 ,chemiluminescent ,reactions with ,physiologic ,substances4 ,journ4 ,am4 ,chem4 ,soc41 vol4 xxxv1 pp4 #hbd-hbf4 ,,mcdermott1 ,f4 ,a43 #aiae1 ,experiments on the ,nature of the ,photogenic ,processes in the ,lampyridae4 ,journ4 ,amer4 ,chem4 ,soc41 vol4 xxxvii1 pp4 #dja-djd4 ,,mckenney1 ,r4 ,b43 #aijb1 ,observations on the ,conditions of ,light ,production in ,luminous ,bacteria4 ,proc4 ,biol4 ,soc41 ,wash41 vol4 xv1 pp4 #bac-bcd4 ,,mcintosh1 ,w4 ,c43 #ahhe1 ,address on ,phosphorescence of ,marine ,animals4 ,nature1 vol4 xxxii1 pp4 #dgf-dha4 ,,meyer1 ,w4 ,,th43 #aijf1 ,ueber das ,leuchtorgan der ,sepiolini4 ,zool4 ,anz41 ,bd4 xxx1 pp4 #chh-cib4 ,,michaelis1 ,g4 ,a43 #ahcj1 ,ueber das ,leuchten der ,ostsee nach eigenen ,beobachtungen4 ,hamburg4 ,,molisch1 ,h43 #aije1 ,luminosity in ,plants4 ,ann4 ,rept4 ,smithsonian ,inst41 pp4 #cea-cfb 7,no4 #afhe74 ,,moore1 ,b43 #aijh1 ,observations on ,certain ,organisms of 7a7 ,variations in ,relation to ,light and 7b7 a ,diurnal ,periodicity of ,phosphorescence4 ,biochemical ,jour41 vol4 iv1 pp4 #a-bi4 ,,muraoka1 ,h43 #ahif1 ,das ,johanniskaeferlicht4 ,wiedemann's ,ann4 d4 ,physik41 ,n4 ,f41 ,bd4 lix1 pp4 #ggc-gha4 ,,muraoka1 ,h43 #ahig1 ,das ,johanniskaeferlicht4 ,journ4 of the ,coll4 of ,science1 ,univ4 ,japan1 vol4 ix1 p4 #abi4 ,,nadson1 ,g43 #aijb1 ,sur la phosphorescence des ,bacteries4 ,rapport fait a la ,soc4 ,microbiologie1 ,st4 ,petersbourg1 ,march #bith4 ,,nadson1 ,g43 #aijc1 ,sur la phosphorescence des ,bacteries4 ,bull4 du jardin ,imper4 botan4 de ,st4 ,petersbourg1 ,t4 iii1 pp4 #aaj-abb4 ,,nadson1 ,g43 #aijh1 ,zur ,physiologie der ,leuchtbacterien4 ,bull4 ,jard4 ,imp4 ,bot4 de ,st4 ,petersbourg1 vol4 viii1 p4 #add4 ,,nichols1 ,e4 ,l41 and ,,merritt1 ,e43 #aiab1 ,studies in ,luminescence4 ,pub4 ,carneg4 ,inst41 ,wash41 ,no4 #aeb1 pp4 #a-bbc4 ,,nutting1 ,c4 ,c43 #aijg1 ,the ,theory of ,abyssal ,light4 ,proc4 ,seventh ,internat4 ,zool4 ,cong41 ,boston1 pp4 #hhi-hii4 ,,nutting1 ,p4 ,g43 #aijh1 ,the ,luminous ,equivalent of ,radiation4 ,bull4 ,bur4 ,standards1 ,washington1 ,d4 ,c41 vol4 v1 pp4 #bfa-jci4 ,,nutting1 ,p4 ,g43 #aiaa1 ,the ,visibility of ,radiation1 a ,recalculation of ,konig's ,data4 ,bull4 ,bur4 ,standards1 ,washington1 ,d4 ,c41 vol4 vii1 pp4 #bce-bdc4 ,,osborne1 ,t4 ,b4 and ,,wakeman1 ,a4 ,j43 #aiah1 ,some ,new ,constituents of ,milk4 ,a ,new ,protein ,soluble in ,alcohol4 ,j4 ,biol4 ,chem41 vol4 xxxiii1 p4 #bdc4 ,,oshima1 ,h43 #aiaa1 ,some ,observations on the ,luminous ,organs of ,fishes4 ,jour4 ,coll4 ,sc41 ,tokio1 vol4 xxvii4 ,,otto1 ,m43 #ahif1 ,sur l'ozone et les phenomenes de phosphorescence4 ,c4 ,r4 ,ac4 ,sc41 vol4 cxxlii1 p4 #ajje4 ,,owsjannikow1 ,p43 #ahfd-ahfh1 ,zur ,kenntnis der ,leuchtorgane der ,lampyris noctiluca4 ,mem4 ,ac4 ,st4 ,petersb41 ,ser4 #b1 vol4 xi2 also ,bull4 ,ac4 ,so41 #ahfd1 vol4 viii4 ,,panceri1 ,p43 #ahgb1 ,etudes sur la phosphorescence des animaux marins4 ,ann4 d4 ,sc4 ,nat41 #e ,ser4 ,zool41 ,t4 xvi4 ,,panceri1 ,p43 #ahgg1 ,luminous ,campanulariae4 ,nature1 vol4 xvi1 p4 #cj4 ,,pasteur3 #ahfd1 ,sur la lumiere phosphorescente des ,cucujos4 ,comp4 rend4 ,acad4 ,sc41 ,t4 lix1 p4 #eji4 ,,peron1 ,f43 #ahjd1 ,memoire sur le nouveau genre ,pyrosoma4 ,ann4 du ,mus4 d'hist4 ,nat41 vol4 iv1 #dcg-ddf4 ,,peters1 ,a4 ,w43 #aije1 ,phosphorescence in ,ctenophores4 ,journ4 of ,exper4 ,zool41 vol4 ii1 p4 #ajc ,p,f,l,ue,g,e,r1 ,e43 #ahge;a1 ,die ,phosphorescenz lebendinger ,organismen und ihre ,bedeutung fuer die ,principien der ,respiration4 ,arch4 f4 die ges4 ,physiol41 vol4 x1 p4 #bge4 ,p,f,l,ue,g,e,r1 ,e43 #ahge;b1 ,ueber die ,phosphorescenz verwesender ,organism4 ,arch4 f4 d4 ges4 ,physiol41 ,bd4 xi1 pp4 #bbb-bfc4 ,,phipson1 ,t4 ,l43 #ahfj1 ,sur la matiere phosphorescente de la raie4 ,compt4 rend4 ,acad4 d4 ,sc41 ,t4 li1 p4 #eda4 ,,phipson1 ,t4 ,l43 #ahgb1 ,sur la noctilucine4 ,c4 ,r4 ,ac4 ,sc41 ,t4 lxxv1 p4 #edg4 ,,phipson1 ,t4 ,l43 #ahgf1 ,on ,noctilucine1 the ,phosphorescent ,principle of ,luminous ,animals4 ,journ4 ,franklin ,inst41 vol4 ci1 pp4 #fh-gb4 ,,pierantoni1 ,,umberto3 #aiah1 ,les microorganismes physiologiques et la luminescence des animaux4 ,scientia1 vol4 xxiii1 p4 #dc4 ,,polimanti1 ,,oswald3 #aiaa1 ,ueber das ,leuchten von ,pyrosoma elegans ,les4 ,zeitschrift f4 ,biol41 vol4 lv1 pp4 #eje-ebi4 ,,pope1 ,w4 ,j43 #ahii1 ,on ,triboluminescence4 ,nature1 vol4 lix1 p4 #fah4 ,,prevost1 ,,benedict3 #ahaj1 ,considerations sur le brillant des yeux du chat et de quelques autres animaux4 ,bibl4 ,britt4 ,sc4 et ,arts1 vol4 xlv1 pp4 #aif-bab4 ,p,ue,t,t,e,r1 ,a43 #aije1 ,leuchtende ,organismen4 ,ztschr4 f4 ,allg4 ,physiol41 ,bd4 v1 ,sammelreferate1 pp4 #ag-ec4 ,,quatrefages1 ,a4 ,,de3 #ahdc1 ,note sur un nouveau mode de phosphorescence observe chez quelques ,annelides et ,ophiures4 ,ann4 d4 ,sc4 ,nat41 #bnd ser41 ,zool41 ,t4 xix1 pp4 #ahc-aib4 ,,quatrefages1 ,a4 ,,de3 #ahej1 ,observations sur les noctiluques4 ,ann4 d4 ,sc4 ,nat41 #crd ,ser41 ,zool41 ,t4 xiv1 pp4 #bbf-bce4 ,,quatrefages1 ,a4 ,,de3 #ahej1 ,memoire sur la phosphorescence de quelques invertebres marins4 ,ann4 d4 ,sc4 ,nat41 #c ser41 ,zool41 ,t4 xiv1 pp4 #bcf-bha4 ,,quatrefages1 ,a4 ,,de3 #ahfb1 ,the ,phosphorescence of the ,sea4 ,popular ,sc4 ,rev41 vol4 i1 pp4 #bge-bih4 ,,radziszewski1 ,b43 #ahgg1 ,untersuchungen ueber ,hydrobenzamid1 ,amarin und ,lophin4 ,ber4 d4 d4 chem4 ,ges41 vol4 x1 pp4 #gj-ge and pp4 #cba-cbb4 ,,radziszewski1 ,b43 #ahhj1 ,ueber die ,phosphorescenz der organischen und organisierten ,koerper4 ,liebigs ,ann41 ,bd4 #bjc1 pp4 #cje-ccf4 ,,radziszewski1 ,b43 #ahhc1 ,zur ,theorie der ,phosphorescenzerscheinungen4 ,ber4 d4 d4 ,chem4 ,ges41 vol4 xvi1 pp4 #eig-fja4 ,,reeves1 ,p43 #aiag1 ,the ,minimum ,radiation ,visually ,perceptible4 ,commun4 ,no4 #ea1 ,research ,lab4 ,eastman ,kodak ,co41 pp4 #afg-agd4 ,,reichensperger1 ,a43 #aijh1 ,ueber ,leuchten von ,schlangensternen4 ,biol4 ,ctbl41 ,bd1 xxviii1 p4 #aff-afi4 ,,reinelt1 ,j43 #aijf1 ,beitraege zur ,kenntnis einiger ,leuchtbacterien4 ,centralb4 f4 ,bakt41 vol4 xv41 pp4 #bhi-cjj4 ,,reinke1 ,j43 #ahih1 ,ueber das ,leuchten von ,ceratium tripos4 ,wiss4 ,meeresunters41 herausgeg4 ,v4 d4 ,kommiss4 z4 wiss4 ,unters4 d4 deutsch4 ,meers4 in ,kiel u4 d4 ,biol4 ,station auf ,helgoland1 ,n4 ,f41 ,bd4 iii1 ,abt4 ,kiel1 p4 #cg4 ,,richter1 ,o43 #aijf1 ,chlorophyllbildung im ,bakterienlichte4 ,sitz4 ber4 d4 k4 k4 ,akad4 d4 ,wiss4 ,wien4 ,math4 nat4 ,kl41 ,bd4 #aae1 i1 p4 #bih4 ,,robin1 ,,ch4 et ,,laboulbene1 ,a43 #ahgc1 ,sur les organes phosphorescents thoraciques et abdominals du ,cocuyo de ,cuba 7,pyrophorus noctilucus1 ,l474 ,compt4 rend4 ,acad4 d4 ,sc4 ,paris1 ,t4 lxxvii1 pp4 #eaa-eag4 ,,russell1 ,w4 ,j43 #ahig1 ,on the ,action ,exerted by ,certain ,metals and ,other ,substances on a ,photographic ,plate4 ,proc4 ,roy4 ,soc41 vol4 lxi1 pp4 #dbd-dcc4 ,,russell1 ,e4 ,j43 #aijc1 ,the ,reaction between ,phosphorus and ,oxygen1 ,part ,i4 ,jour4 ,chem4 ,soc41 vol4 lxxxiii1 pp4 #abfc-abhd4 ,,sasaki1 ,m43 #aiad1 ,observations on ,hotaru-ika1 ,watasenia scintillans4 ,jour4 ,coll4 ,agric4 ,sapporo1 ,japan1 vol4 vi1 pp4 #ge-aje4 ,,scharff1 ,e43 #aijh1 ,ueber das ,leuchten des ,phosphors und einiger ,phosphorverbindungen4 ,zeit4 physik4 ,chem41 vol4 lxii1 pp4 #agi-aic4 ,,schmidt1 ,p43 #ahid1 ,ueber das ,leuchten der ,zuckmuecken 7,chironomidae74 ,zool4 ,jahrb4 ,abth4 ,syst41 #h ,bd41 pp4 #eh-ff4 ,trans4 in ,ann4 ,mag4 ,nat4 ,hist41 7#f71 vol xv1 pp4 #acc-ada4 ,,schultze1 ,c4 ,a4 ,s43 #ahhf1 ,beobachtungen an ,noctiluca4 ,arch4 f4 ,mikrosk4 ,anat41 ,bd4 ii1 p4 #afc4 ,,schultze1 ,,max3 #ahfe1 ,zur ,kenntnis der ,leuchtorgane von ,lampyris splendidula4 ,arch4 f4 mikrosk4 ,anat41 ,bd4 i1 pp4 #abd-acg4 ,,schurig1 ,w43 #aija1 ,biologische ,experimente nebst ein ,einhang ,microscopische ,technik4 ,leipzig1 p4 #aca4 ,,shoji1 ,r43 #aiai1 ,a ,physiological ,study on the ,luminescence of ,watasenia scintillans 7,berry74 ,amer4 ,jour4 ,physiol41 vol4 xlvii1 pp4 #ecd-eeg4 ,,singh1 ,p41 and ,,maulik1 ,s43 #aiaj1 ,nature of ,light ,emitted by ,fireflies4 ,nature1 vol4 lxxxviii1 p4 #aaa4 ,,sokolow1 ,,iwan3 #aiji1 ,zur ,frage ,ueber das ,leuchten und die ,druesengebilde der ,ophiuren4 ,biol4 ,ctbl41 ,bd4 xxix1 pp4 #fcg-fdh4 ,,spallanzani1 ,,lazzaro3 #agid1 ,memoria sopra le ,meduse fosforiche4 ,mem4 ,soc4 ,ital4 ,verona1 vol4 vii1 pp4 #bga-bij4 ,,steche1 ,o43 #aijh1 ,beobachtungen ueber das ,leuchten tropischer ,lampyriden4 ,zool4 ,anz41 ,bd4 xxxii1 pp4 #gaj-gab4 ,,steche1 ,o43 #aiji1 ,ueber die ,leuchtorgane von ,anomalops katoptron und ,photoblepharon palpebratus1 zwei ,oberflaechenfischen aus dem ,malaysichen ,archipel4 ,ein ,beitrag zur ,morph4 u4 ,physiol4 der ,leuchtorgane der ,fische4 ,ztschr4 f4 wiss4 ,zool41 ,bd4 xciii1 pp4 #cdi-djh4 ,,sterzinger1 ,i43 #aijg1 ,ueber das ,leuchtvermoegen von ,amphiura squamata1 ,sars4 ,ztschr4 f4 wiss4 ,zool41 ,bd4 lxxxviii1 pp4 #ceh-chd4 ,s,t,ue,b,e,l1 ,h43 #aiaa1 ,die ,fluorescence tierische ,gewebe in ultra-violett ,licht4 ,arch4 f4 d4 ges4 ,physiol1 vol4 cxlii1 pp4 #a-ad4 ,,suchsland1 ,e43 #ahih1 ,physikalische ,studien ueber ,leuchtbakterien4 ,festschr4 d4 #bjj-;jaehr4 ,jubelfeier der ,franckeschen ,stiftungen1 ,halle1 p4 #hg4 ,ref4 in ,zentralb4 f4 ,bact41 ,,ii ,abt4 iv1 pp4 #gac-gae4 ,,tarchanoff1 ,j43 #aija1 ,lumiere des bacilles phosphorescents de la mer ,baltique4 ,compt4 rend4 ,acad4 d4 ,sc4 ,paris1 #aija1 ,t4 cxxxiii1 pp4 #bdf-bdi4 ,,tarchanoff1 ,j43 #aijb1 ,biologisch-chemische ,untersuchungen der ,phosphorescierenden ,bakterien4 7,russ474 ,journ4 med4 chim4 ,st4 ,petersbourg1 ,bd4 xxv-xxvi1 pp4 #ef-gd4 ,,terao1 ,a43 #aiag1 ,notes on ,photophores of ,sergestes prehensilis1 ,bate4 ,annot4 ,zool4 ,japan1 vol4 ix1 pp4 #bii-caf4 ,,thomas1 ,r4 ,h43 #aijb1 ,a ,luminous ,centipede4 ,nature1 vol4 lxv1 p4 #bbc4 ,,tollhausen1 ,p43 #ahhi1 ,untersuchungen ueber ,bacterium phosphorescens ,fischer4 ,diss4 ,wuerzburg4 ,,tommasino1 ,,th43 #aijd1 ,constatation d'une radioactivite propre aux etres vivants1 vegetaux et animaux4 ,compt4 rend4 ,acad4 d4 ,sc41 ,bd4 cxxxix1 pp4 #gcj-gca4 ,,townsend1 ,a4 ,b43 #aijd1 ,histology of the ,light ,organs1 of ,photinus marginellus4 ,amer4 ,nat41 #aijd1 vol4 xxxviii1 pp4 #abg-aea4 ,,trautz1 ,m43 #aijd1 ,ueber neue ,lumineszenzerscheinungen4 ,zeit4 wiss4 ,photogr41 vol4 ii1 pp4 #bag-bbc2 also1 ,zeit4 f4 ,electrochem41 vol4 x1 pp4 #eic-eig4 ,,trautz1 ,m43 #aije1 ,studien ueber ,chemilumineszenz4 ,ztschr4 physikal4 ,chem41 vol4 liii1 pp4 #a-aaa4 ,,trautz1 ,m41 and ,,schorigin1 ,p43 #aije;a1 ,kristallolumineszenz und ,tribolumineszenz4 ,zeit4 wiss4 ,photog41 vol4 iii1 pp4 #hj-ij4 ,,trautz1 ,m41 and ,,schorigin1 ,p43 #aije;b1 ,ueber ,chemilumineszenz4 ,zeit4 wiss4 ,photog41 vol4 iii1 pp4 #aba-acj4 ,,trojan1 ,e43 #aijf1 ,neuere ,arbeiten ueber die ,leuchtorgane der ,fische4 ,zool4 ,ctbl41 ,bd4 xiii1 pp4 #bgc-bhd4 ,,trojan1 ,e43 #aijg1 ,zur ,lichtentwicklung in den ,photosphaerien der ,euphausien4 ,arch4 f4 mikr4 ,anat41 ,bd4 lxx1 pp4 #agg-ahh4 ,,trojan1 ,e43 #aiji1 ,leuchtende ,ophiopsilen4 ,arch4 f4 mikr4 ,anat41 ,bd4 lxxiii1 pp4 #hhc-iab4 ,,trojan1 ,e43 #aiaj1 ,ein ,betrag zur ,histologie von ,phyllirhoe bucephala4 ,peron und ,lesueur4 mit besonderer ,beruecksichtigung des ,leuchtvermoegens des ,tieres4 ,arch4 microscop4 ,anat41 vol4 lxxv1 pp4 #dgc-eag4 ,,trojan1 ,e43 #aiac1 ,ueber ,hautdruesen des ,chaetopterus variopedatus1 ,clap4 ,sitz4 ber4 d4 ,kais4 ,ac4 d4 wiss4 ,wein41 vol4 cxxii1 ,abt4 #a4 ,,trojan1 ,e43 #aiae1 ,die ,leuchtorgane von ,cyclothone ,signata1 ,garman4 ,sitz4-ber4 d4 ,k4 ,akad4 der wiss4 ,wien41 ,bd4 cxxiv1 ,abt4 #a4 ,,tschugaeff1 ,l43 #aija1 ,ueber ,tribolumineszenz4 ,ber4 d4 d4 chem4 ,ges41 vol4 xxxiv1 pp4 #ahbj-ahbf4 ,,vallentin1 ,r41 and ,,cunningham1 ,j4 ,t43 #ahhh1 ,the ,photospheria of ,nyctiphanes ,norvegica4 ,quart4 ,journ4 of ,micr4 ,sc41 ,n4 ,s41 vol4 xxviii1 pp4 #cai-cda4 ,,van',t ,,hoff1 ,j4 ,h43 #ahie1 ,ueber die menge und die ,nature des sogen4 ,ozons das sich bei langsamer ,oxidations des ,phosphors bildet4 ,zeit4 physik4 ,chem41 vol4 xvi1 pp4 #daa-daf4 ,,verrill1 ,a4 ,e43 #ahhd1 ,evidences of the ,existence of ,light at ,great ,depths in the ,sea4 ,nature1 vol4 xxx1 pp4 #bhj-bha4 ,,verworn1 ,m43 #ahib1 ,ein automatisches ,zentrum fuer die ,lichtproduktion bei ,luciola italica ,l4 ,ctbl4 f4 ,physiol41 ,bd4 vi1 pp4 #fi-gd4 ,,vignal1 ,w43 #ahgh1 ,recherches histologiques et physiologiques sur les ,notiluques4 ,arch d4 ,physiol4 ,norm4 et ,patholog41 #bnd ser41 ,t4 v1 pp4 #dae-ded4 ,,ville1 ,j41 and ,,derrien1 ,e43 #aiac1 ,catalyse biochemique d'une oxydation luminescente4 ,c4 ,r4 ,ac4 ,sc41 vol4 clvi1 p4 #bjba4 ,,vogel41 ,r43 #aiae1 ,beitrag zur ,kenntnis des ,baues und der ,lebensweise der ,larve von ,lampyris noctiluca4 ,zeit4 wiss4 ,zool41 vol4 cxii1 pp4 #bia-dcb4 ,,watanabe1 ,h43 #ahig1 ,the ,phosphorescence of ,cypridina hilgendorfii4 ,annot4 ,zool4 ,japan1 vol4 i2 also1 ,zool4 ,jahrs41 #ahig4 ,,watase1 ,s43 #ahie1 ,on the ,physical ,basis of ,animal ,phosphorescence4 ,biol4 ,lect4 ,marine ,biol4 ,lab4 ,woods ,hole1 pp4 #aja-aai4 ,,watase1 ,s43 #ahih1 ,protoplasmic ,contractility and ,phosphorescence4 ,biolog4 ,lect4 ,marine ,biol4 ,lab4 ,woods ,hole1 pp4 #agg-aib4 ,,weiser1 ,h4 ,b43 #aiah;a1 ,color ,determination of ,faint ,luminescence4 ,journ4 ,phys4 ,chem41 vol4 xxii1 pp4 #dci-ddi4 ,,weiser1 ,h4 ,b43 #aiah;b1 ,crystalloluminescence1 ,i1 ,,ii4 ,journ4 ,phys4 ,chem41 vol4 xxii1 pp4 #dhj-eji1 and pp4 #egf-eie4 ,,weitlaner1 ,f43 #aiji1 ,etwas von ,johannis-,kaeferlicht4 ,verh4 d4 ,zool4 ,bot4 ,ges4 ,wein41 vol4 lix4 ,,weitlaner1 ,f43 #aiaa1 ,weiteres vom ,johanniskaeferlicht und von ,organismenleuchten uberhaupt1 etc4 ,verh4 d4 ,zool4 ,bot4 ,ges4 ,wein41 vol4 xli1 p4 #aib4 ,,weleminsky1 ,f43 #ahie1 ,die ,ursachen des ,leuchtens bei ,choleravibrionen4 ,prager med4 ,wochenschr41 ,bd4 xx1 pp4 #bfc-bfd4 ,,welker1 ,w4 ,h43 #aiab1 ,diffusibility of ,protein ,through ,rubber ,membranes with a ,note on the ,disintegration of ,colloidian ,membranes by ,common ,ethyl ,ether and ,other ,solvents4 ,biochem4 ,bull41 vol4 ii1 p4 #gj4 ,,wheeler1 ,w4 ,m41 and ,,williams1 ,f4 ,x43 #aiae1 ,the ,luminous ,organ of the ,new ,zealand ,glowworm4 ,psyche1 vol4 xxii1 pp4 #cf-dc4 ,,weidemann1 ,e43 #ahhh1 ,ueber ,fluorescenz und ,phosphorescenz4 ,wied4 ,ann4 d4 ,phy4 u4 ,chem41 vol4 xxxiv1 pp4 #ddf-dfi4 ,,wiedemann1 ,e41 and ,,schmidt1 ,g4 ,w43 #ahie;a1 ,ueber ,luminescenz4 ,wied4 ,ann4 d4 ,phy4 u4 ,chem41 vol4 liv1 pp4 #fjd-fbe2 #ahie;b1 vol4 lvi1 pp4 #bja-bed4 ,,wielowiejski1 ,h4 ,r4 ,v43 #ahhb1 ,studien ueber die ,lampyriden4 ,ztschr4 f4 wiss4 ,zool41 ,bd4 xxxvii1 pp4 #ced-dbh4 ,,williams1 ,f4 ,x43 #aiaf1 ,photogenic ,organs and ,embryology of ,lampyrids4 ,journ4 ,morph41 vol4 xxviii1 pp4 #ade-ahf4 ,,yatsu1 ,n43 #aiag1 ,note on the ,structure of the ,maxillary ,gland of ,cypridina hilgendorfii4 ,journ4 ,morph41 vol4 xxix1 pp4 #dce-ddj4 ,,young1 ,c4 ,a43 #ahgj1 ,the ,spectrum of the ,firefly4 ,amer4 ,nat41 vol4 iii1 p4 #fae4 ,,zacharias1 ,o43 #aije1 ,beobachtungen ueber das ,leuchtvermoegen von ,ceratium tripos4 ,biol4 ,ctbl41 ,bd4 xxv1 pp4 #bj-cj4 ,,index ,abegg1 ,r41 #adg ,acanthephyra1 #gh ,agaricus1 #ii ,agassiz1 ,a41 #aa ,alkaptonuria1 #ag ,allman1 ,g4 ,i41 #aa1 #ga ,ammonia1 #ab ,anodoluminescence1 #bf1 #bi ,anornalops1 #fi ,aristeus1 #gb ,aristotle1 #a ,bach1 ,a41 #acg ,bacteria1 luminous1 #b1 #aj1 #ac1 #ad1 #af1 #ah1 #bh1 #de1 #ec1 #fa1 #fe1 #fi1 #gb1 #gd1 #ha1 #hb1 #hi1 #ii1 #aja1 #ajc ,bacterial lamps1 #ah ,baker1 ,j41 #b ,bancroft1 ,w4 ,d41 #cf ,bancroft and ,weiser1 #bd ,bandrowski1 ,e41 #cc ,barcroft and ,hill1 #ih ,barnea1 #aaf ,batelli and ,stern1 #aae ,becquerel1 ,e41 #bf ,beijerinck1 ,m4 ,w41 #ah1 #hi1 #ii1 #ajj1 #ajb ,bigelow1 ,s4 ,l41 #cd ,black1 #ia ,bolitophila1 #gg ,boyle1 ,r41 #a1 #af1 #he ff ,brandt1 #cf ,brittle stars or ophiuroids1 #aj1 #aa1 #gb ,canton's phosphorus1 #bg ,carbon dioxide and luminescence1 #ia ff ,cardium1 #aaf ,cascariolo1 ,v41 #bg ,cathodoluminescence1 #bf1 #bi ,cavernularia1 #gd1 #ajc ,centnerzwer1 ,m41 #adg ,cephalopods or ,squid1 #aj1 #aa1 #ac1 #fh1 #gb1 #hd1 #ajd ,ceratium1 #ga ,chaetopterus1 #aj1 #ag1 #db1 #ga1 #gc1 #gd1 #hc1 #ajc ,chemiluminescence1 #cf ff1 #de ff ,chlorophyll formation by animal light1 #ff ,chromophyton1 #ae ,chun1 ,c41 #gi ,coblentz1 ,w4 ,w41 #cj1 #ca1 #dd1 #ea1 #eb1 #ei1 #fj1 #fb1 #fd1 #ic1 #afj4 ,co-enzyme1 #ajd1 #acj ,co-luciferase1 #ajg ff ,color of animal light1 #da ff1 #aeg ff ,concentration and luminiscence1 #ade ff ,conroy1 ,j41 #dc ,crozier1 ,w4 ,j41 #ga1 #ajc ,crustacea1 #aj1 #ad1 #fh1 #gj1 #gb1 #hi1 #aja ff ,crysalloluminescence1 #cc ff1 #gd ,ctenophores1 #b1 #aj1 #aa1 #ga1 #gb1 #hb ,cyanides and luminescence1 #abf ,cypridina1 #ad1 #cj1 #de1 #dh1 #fc1 #ga1 #gc1 #ge ff1 #ij1 #ib1 #ih1 #ajc1 #aje ff1 #aee ff ,dahlgren1 ,u41 #gb1 #gc1 #ge ,death ,glow1 #fi ,dinoflagellates1 #b1 #aj1 #cb1 #hb ,dubois1 ,r41 #ca1 #ce1 #cg1 #dc1 #de1 #di1 #fa1 #fd1 #gc1 #ajc ff1 #aaa1 #aad ff1 #aca1 #aee ,earthworms1 #aj ,efficiency of animal light1 #dh ff ,eggs1 luminous1 #aa ,electroluminescence1 #bd1 #bi ,embryos1 luminous1 #aa ,euphasia1 #gb ,ewan1 ,t41 #adg ,exner1 ,s41 #cj ,extracellular luminescence1 #fh1 #ga ,eyes1 luminous1 #ae ff ,fabre ,j4 ,h41 #ii ,fahrig1 ,e41 #cg ,fireflies1 #aj1 #ca1 #cd1 #dc1 #fi1 #ga1 #gg ff1 #hi1 #ic1 #aja1 #ajc1 #ace1 #afj ,fishes1 #a1 #c1 #aj1 #ah1 #fd1 #fi1 #gb1 #hd1 #he ,flowers1 flashing of1 #af ,fluorescence1 #be ff1 #fb ,fluorescent screens1 #bi ,forsyth1 ,r4 ,w41 #ec ,frankland1 ,p41 #fb ,friedberger ,doepner1 #fe ,frogs1 luminous1 #ac ,fungi or ,basidiomycetes1 #aj1 #fi1 #gb1 #ha1 #hi1 #ii1 #aja ,galloway and ,welch1 #hd ,gernez1 ,d41 #cb ,giard and ,billet1 #ac ,giesbrecht1 ,w41 #aa1 #gj ,glowworms1 #a1 #aj1 #dc1 #gg ,gnathophausia1 #gb ,goss1 ,b4 ,c41 #adc ,greene1 ,c4 ,w41 #gj ,guinchant1 #cg ,h-ion concentration and luminescence1 #ib1 #ach1 #aee ,heat production and luminescence1 #ic ff ,heliotropism by animal light1 #ff4 ,heller1 ,j4 ,f41 #a1 #b1 #af ,heterocarpus1 #gb ,heteroteuthis1 #gb ,hooke1 ,r41 #ia ,hulme1 ,n41 #a ,hyde1 ,forsyth and ,cady1 #eg1 #fc ,hydrogenase1 #aca ,hydroils1 #aj1 #gb ,ignis fatuus1 #ae ,immune bodies1 #ajd ,infection1 with luminous bacteria1 #ac ,infra red rays in animal light1 #dh ff ,intensity of animal light1 #fc ,intracellular ,luminescence1 #fh1 #ga ,interference colors1 #ad ,issatschenko1 ,b41 #ff ,ives1 ,h4 ,e41 #bh1 #dd1 #ea ff1 #ei1 #fa ,kemp1 ,c41 #gh ,langley and ,very1 #dc1 #ej ff1 #fd ,lankester1 ,e4 ,r41 #db ,lavoisier1 #ia ,lenard and ,wolf1 #cg ,ligia1 #ac ,limulus1 #abi ,linnemann1 ,e41 #cf ,lode1 ,a41 #fe ,luciferase1 #ajc ff4 ,chap ,,vi 7properties72 of ,pholas1 #aad2 of ,cypridina1 #abc ff ,luciferesceine1 #ca1 #aaj ,luciferin1 #ajc ff4 ,chap4 ,,vi 7properties72 of ,pholas1 #aad2 of ,cypridina1 #aaf ff ,luciola1 #ajc1 #abe4 ,luminescence1 #bc ff ,luminosity1 distribution in plant and animal kingdom1 #c to #ab ,luminosity1 false1 #ab ff ,luminous animals1 habitat1 #aj ,luminous animals1 uses of to man1 #ag ff ,luminous granules1 #gc1 #ge ,lyman rays1 #ba ,lyoluminescence1 #ce ,mac,cartney1 ,j41 #b1 #c ,macfayden1 ,a41 #aeg ,macrozymases1 #gc ,man1 luminosity of1 #af ,mangold1 ,e41 #aa1 #gb ,massart1 ,j41 #ga ,mast1 ,s4 ,o41 #fi ,mayow1 #ia ,mc,dermott1 ,f4 ,a41 #ca1 #cg1 #de1 #ec ,mc,kenney1 ,r4 ,b41 #ajj ,medusae or jelly fish1 #b1 #aj1 #gb1 #hb ,methane1 #ae4 ,michaelis1 ,g4 ,a41 #a ,minimum radiation visually perceptible1 #fe1 #add ,molisch1 ,h41 #de1 #ec1 #fa1 #ff1 #ajb ,molluscs1 #aj1 #gb ,monocentris1 #fi1 #ajd ,moore1 ,b41 #ga ,muraoka1 ,h41 #fa ,myriapods1 #aj1 #ce1 #gb ,mytilus1 #aaf ,nadson1 ,g41 #ff ,nematocelis1 #gb ,noctiluca1 #b1 #aj1 #ga1 #gc1 #hb1 #hc1 #hi1 #ajd ,noctilucin1 #aja ,nutting1 ,p4 ,g41 #eg1 #ei ,nyctiphanes1 #gb1 #hj ,odontosyllis1 #hc ,orchestia1 #ac ,orya1 #ce ,osborne and ,wakeman1 #aba ,ostraea1 #aaf ,otto1 ,m41 #cg ,oxygen and luminescence1 #a1 #fg1 #he ff1 #adg ff ,oxyluciferine1 #ajh ff1 #abg ff1 #aeh ,oxyluminescence1 #cf ff1 #aaa ff ,paint1 luminous1 #bh1 #bi ,panceri1 ,p41 #de1 #gd ,pasteur1 #db ,penetrating radiation in animal light1 #fa ff ,pennatula1 #gd1 #ajc ,pennatulids or sea pens1 #aj1 #gb1 #gd1 #hb1 #hc1 #hi1 #aja1 #ajc ,peridineae1 #aj ,periodicity of luminescence1 #ga ,peron1 ,f41 #de ,peroxidases1 #aa1 #abf1 #adh ,peters1 ,a4 ,w41 #aa1 #ga ,pflueger1 ,e41 #a1 #ajb ,phengodes1 #da1 #db ,phillips1 ,a4 ,h41 #abe ,philoscia1 #ac ,phipson1 ,t4 ,l41 #aja1 #aji1 #aaj ,pholas1 #aj1 #aa1 #gb1 #gc1 #gd1 #hi1 #aja1 #ajc1 #aje ff1 #aad ff1 #aca ,phosphine1 #ae ,phosphorescence1 #bd1 #be ff1 #ach1 #adc ,phosphoroscope1 #bf ,phosphor-photographic method1 #eb ,phosphorus and luminescence1 #ch1 #ci1 #adg ff ,photinus1 #dd1 #ea1 #ec1 #ef1 #ei1 #fd1 #ajc1 #abe1 #afj ff ,photoblepharon1 #ah1 #fd1 #fi ,photochemical reactions1 #fg1 #fh1 #ach1 #ade ,photogen1 #ajb ,photogenin1 #aje ,photoluminescence1 #bf1 #fg ,photophelein1 #aje1 #ajf1 #aaj ,photosynthesis by animal light1 #ah ,photuris1 #dd1 #ei1 #ajc1 #abe1 #afj ff ,pierantoni1 ,v41 #ac1 #ad1 #gd ,piezoluminescence1 #cb ff ,polarization1 #de ,polimanti1 ,o41 #de ,pope1 ,w4 ,j41 #cb ,porcellio1 #ac ,porichthys1 #gj1 #hc ,preluciferine or proluciferine1 #ajf ff ,prevost1 ,b41 #ae ,priestly1 #ia ,ptychodera1 #ga1 #ajc ,purkinje phenomenon1 #dj1 #dd1 #aeg ,pyrogallol and luminescence1 #cg1 #aaa1 #adh ff ,pyroluminescence1 #bd ,pyrophorine1 #ca1 #aji ,pyrophorus1 #aa1 #dc1 #de1 #di ff1 #fd1 #gf1 #aja1 #ajc1 #aad1 #abe ,pyrosoma1 #aj1 #ac1 #de1 #gb1 #aja ,quatrefages1 ,a4 de41 #gc ,radiant energy1 #bj ff ,radioluminescence1 #bf ,radium rays or ,becquerel rays1 #ba1 #bf1 #cj1 #fb ,radziszewski1 ,b41 #cg1 #ci ,reaction velocity and luminescence1 #ade ff ,reductase1 #acj ff ,reeves1 ,p41 #fe1 #add ,respiration and luminescence1 #ia1 #ib1 #ii ,rhizomorpha1 #b ,romberg's phosphorus1 #cb ,russel1 ,e4 ,j41 #adg ,russel1 ,w4 ,j41 #fb ,sapphirina1 #ad ,sarcina1 #a ,scharff1 ,e41 #adg ,scheele1 #ia ,schistostega1 #ae ,schizopod larvae1 #aa ,schumann rays1 #ba ,schurig1 ,w41 #fa ,scolopendra1 #ajb ,sea1 phosphorescence of1 #b ,sepietta1 #gb ,sergestes1 #gb1 #gh ,singh and ,maulik1 #fa ,solen1 #aaf ,spallanzani1 ,l41 #he1 #aja ,spectrum of chemiluminescence1 #ci ,spectrum of luminous organisms1 #db ff ,spectrum of phosphorescence1 #bh ,spectrum1 range of1 #ba ff ,spinthariscope1 #cj ,steche1 ,o41 #fe1 #fi ,stefan-,boltzmann ,law1 #bb1 #bc ,stimulation and luminescence1 #fh ff1 #ace ,stoke's ,law1 #bh1 #ca ,stylochiron1 #gb ,suchsland1 ,e41 #fa ,sulphides1 phosphorescence of1 #bg ,sweat1 luminous1 #ag ,talitrus1 #ac ,tarchanoff1 ,j41 #ac ,temperature and luminescence1 #ade ff1 #aef ff ,temperature radiation1 #bc ,thaumatolampas1 #db ,thermoluminescence1 #bd ff ,tomopterus1 #gb ,transparency of chitin to infra-red1 #eb ,trautz1 ,m41 #cb1 #cc1 #cg1 #ci1 #ade ,triboluminescence1 #cb ff ,trojan1 ,e41 #aa1 #gh ,tschugaeff1 ,l41 #cb ,ultra violet rays in animal light1 #ec ff ,urine1 luminous1 #ah ,uses of luminous organs1 #ha ff ,vacuolides1 #gc van ,helmont1 #ia van't ,hoff1 ,j4 ,h41 #adg ,vibrio1 #fe ,ville and ,derrien1 #aaa ,visual sensibility1 #ed ff ,watanabe1 ,h41 #ge ,watasenia1 #ajd ,water and luminescence1 #he1 #aja ,weiser1 ,h4 ,b41 #cc1 #cd1 #ci ,welker1 ,w4 ,h41 #aba ,wheeler and ,williams1 #gg ,wiedemann1 ,e41 #bc ,wiedemann and ,schmidt1 #be1 #cf ,will-o'-the-wisp1 #ae ,wood1 phosphorescent or shining1 #a1 #b1 #he ,worms or annelids1 #c1 #gb ,x-rays or ,roentgen rays1 #ba1 #bf1 #cj1 #fb ,yatsu1 ,n41 #ge ,young1 ,c4 ,a41 #dc ,zacharias1 ,o41 #ga ,zymogen granules1 #gc 99 99 99 99 99 ,transcriber's ,notes ,uncommon forms for chemical names have been retained where they occur in the text1 e4g4 atropin for atropine2 asparagin for asparagine1 etc4 ,the spellings of ,sidot blend and ,sidot blende are used interchangeably4 ,,ph or ,p,h 7subscript ,h7 is used throughout for the scale of alkali-acidity where the modern usage is p,h4 ,on page #agc1 the citation for ,,nutting1 ,p4 ,g43 #aijh has page range pp4 #bfa-jci4 ,this is as it appears in the original1 but is probably in error4 ,minor corrections to formatting and missing punctuation 7mostly in the bibliography7 have been regularised without an explicit note4 ,where changes to the text have been made in the case of spelling or type-setting errors1 these are listed as follows3 ,page ix3 changed ,phoshorescence to ,phosphorescence 7,,ii4 ,,luminescence ,,and ,,incandescence 444 ,phosphorescence and fluorescence47 ,page ix3 changed ,biozymoxyluminescence to ,biozymooxyluminescence 7,v4 ,,the ,,chemistry ,,of ,,light ,,production1 ,,part ,i 444 ,biozymooxyluminescence47 ,page x3 changed chemi-luminescence to chemiluminescence in two instances 7,reaction velocity and chemiluminescence4 ,temperature and chemiluminescence47 ,page #d1 ,table #a3 changed period ,bacillus4 to comma ,bacillus1 in list7,bacterium1 ,photobacterium1 ,bacillus1 ,pseudomonas1 4447 ,page #e1 ,table #a3 removed comma after ,cunina4 ,page #ae3 changed th to the 7,less well known is the ,ignis fatuus7 ,page #ba1 ,table #b3 changed #af to 4#af 7444 above #ab km4 to 4#af cm47 ,page #bf3 re-positioned period outside of parentheses after being illuminated 7photoluminescence74 ,page #bi3 changed platino-cyanide to platinocyanide 7,fluorescent screens of barium platinocyanide7 ,page #bi3 added missing comma 7willemite 7,zn#b,si,o#d71 ,sidot blend7 ,page #cd3 added missing closing quotation mark 7,it is altogether probable that the cause of this 4447 ,page #ci3 superscript #b changed to subscript #b in ,na#b;,,co#c 7the pyrogallol-formaldehyde-,na#b;,,co#c-;,h #b,o#b reaction7 ,page #da3 #ej-metre candles changed to #ej metre-candles 7,below #j4e and above #ej metre-candles visibility varies 4447 ,page #db1 ,table #d3 changed ,frauenhofer to ,fraunhofer in the caption and table heading 7,fraunhofer ,lines7 ,page #dg1 ,table #e3 changed ,forster to ,foerster 7,bacteria 444 ,foerster1 #ahhg7 ,page #ef1 ,fig #ab caption3 ,forsythe changed to ,forsyth 7after ,hyde1 ,forsyth and ,cady7 ,page #gb3 added missing closing parenthesis the molluscs 7,pholas and ,phyllirhoe7 ,page #gd3 secretion changed to section 7,a section of the epithelium shows large mucous-producing cells 4447 ,page #ge3 added missing closing punctuation 7,at least one1 probably two1 are concerned in light production47 ,page #ge3 changed intra-cellular to intracellular 7animals possessing light cells with intracellular luminescence7 ,page #ha2 ,fig4 #bi caption3 added missing comma 7chr4#a1 chromatophore2 4447 ,page #hg3 added missing closing parenthesis 7and that too of such a ,density to make them continue shining7 ,page #ij3 necesary changed to necessary 7,boyle also made many experiments to show that air was necessary for the life of animals 4447 ,page #ic3 changed thermo-couple to thermocouple 7using a thermocouple as the measuring instrument7 ,page #id3 ,d changed to ,b 7placed in a large ,dewar flask 7,b7 filled with water7 ,page #ig3 thermo-couple changed to thermocouple 7,readings of each thermocouple on the galvanometer scale 4447 ,page #id3 ,thermo-couples changed to ,thermocouples 7,thermocouples 7,l and ,m7 of advance4447 ,page #ajj3 changed ,mc,kenny to ,mc,kenney 7,mc,kenney 7#aijb7 found also 4447 ,page #ajb3 changed misceable to miscible 7insoluble in water but miscible with it7 ,page #ajc3 demontrate changed to demonstrate 7,i have been unable to demonstrate their existence in luminous bacteria27 ,page #ajd3 thermolable changed to thermolabile 7 444and a thermolabile complement 7alexin7 are necessary47 ,page #ajd3 thermolable changed to thermolabile 7,because of the necessity of thermostable and thermolabile substances for light production 4447 ,page #aje3 thermolable changed to thermolabile 7luciferase 7photogenin7 for the thermolabile material 4447 ,page #aaa3 preslence and ,h#b,o#c changed to presence of ,h#b,o#b 7lophin could be oxidized by vertebrate blood in the presence of ,h#b,o#b47 ,page #aaf3 or changed to of 7 444 and would disappear from solution in the course of a day or so47 ,page #aaf3 changed oxidizible to oxidizable 7,the luciferins1 as the oxidizable substances1 must claim first attention47 ,page #abc3 contrated changed to concentrated 7#a c4c4 portions of concentrated luciferin7 ,page #acb3 coluciferase changed to co-luciferase 7,he now regards it as identical with his co-luciferase7 ,page #aea1 ,table #ac3 corrected duplicate numbering #aj to #aa 7#aa ,ferric chloride7 ,page #aea1 ,table #ac3 corrected duplicate numbering #ad to #ae 7#ae ,chromic sulfate7 ,page #aea1 ,table #ac3 abbreviated minute to min4 in two entries 7boiled #a min4 and filtered7 ,page #aeh3 changed appear to appears 7444 and yet light appears only in presence of the latter47 ,page #afb3 added missing closing punctuation 7,more complete works on light and luminescence come first and original articles follow47 ,page #afe3 added missing comma 7,,dubois1 ,r43 #aiah;a1 ,sur la ,synthese de la ,luciferine47 ,page #afe3 changed ,biophotogenesis to ,biophotogenese 7,recherches ,recentes de ,m4 ,newton ,harvey sur la ,biophotogenese7 ,page #afe3 changed ,biophotogenesis to ,biophotogenese 7,nouvelles ,recherches sur la ,biophotogenese7 ,page #aff3 changed ,oxydations geschwindigkeit to ,oxydationsgeschwindigkeit 7,ueber die ,oxydationsgeschwindigkeit von ,phosphor 4447 ,page #aff3 changed ,radiumstrahlem to ,radiumstrahlen 7,einige ,beobachtungen ueber die durch ,radiumstrahlen in den tierischen ,geweben erzeugte ,phosphoreszenz47 ,page #aff3 changed neiderer to niederer 7,ueber die ,entwicklung von ,bakterien bei niederer ,temperatur47 ,page #afg3 changed nueue to neue 7,ueber die rosettenfoermigen ,leuchtorgane der ,tomopteriden und zwei neue ,arten von ,tomopteris47 ,page #afi3 added missing hyphen to ,pflanzen- 7,ueber das ,leuchten im ,pflanzen-und ,tierreiche47 ,page #afi3 changed ,rucksicht to ,ruecksicht 7mit bes4 ,ruecksicht auf4 med4 ,diagnost4 u4 ,therapie ,wien47 ,page #agj3 changed jord4 to jard4 7,bull4 d4 jard4 imp4 botan4 ,st4 ,petersburg7 ,page #aga3 changed ,lichtfauele to ,lichtfaeule 7,phosphorezierende ,tausendfuessler und die ,lichtfaeule des ,holzes7 ,page #agb3 changed ,pfluger's ,arch to ,pflueger's ,arch4 7,pflueger's ,arch41 ,bd4 cxix1 pp4 #ehc-fja47 ,page #agd3 changed ,bedentung to ,bedeutung 7 444 ihre ,bedeutung fuer die ,principien der ,respiration7 ,page #age3 changed ,lazaro to ,lazzaro 7,,spallanzani1 ,,lazzaro3 #agid1 4447 ,page #agf3 changed ,leuchtvermogen to ,leuchtvermoegen 7,ueber das ,leuchtvermoegen von ,amphiura squamata1 ,sars47 ,page #agg3 changed ,triboluminescenz to ,tribolumineszenz 7,,tschugaeff1 ,l43 #aija1 ,ueber ,tribolumineszenz47 ,page #agi3 changed ,bandromski to ,bandrowski 7,bandrowski1 ,e41 #cc7 ,page #agi3 changed ,baelli to ,batelli 7,batelli and ,stern1 #aae7 ,page #agi3 changed ,centnerswer to ,centnerzwer 7,centnerzwer1 ,m41 #adg7 ,page #agi3 changed ,fire-flies to ,fireflies 7,fireflies1 #aj1 #ca1 #cd14447 ,page #ahj3 changed ,forsythe to ,forsyth 7,hyde1 ,forsyth and ,cady1 #eg1 #fc74 ,page #ahj3 changed ,flankland to ,frankland 7,frankland1 ,p41 #fb7 ,page #ahj3 changed ,glow-worms to ,glowworms 7,glowworms1 #a1 #aj1 #dc1 #gg7 ,page #aha3 changed ,piezolumisescence to ,piezoluminescence 7,piezoluminescence1 #cb ff74 ,page #ahb3 changed ,stefan-,boltzman to ,stefan-,boltzmann 7,stefan-,boltzmann ,law1 #bb1 #bc7 ,page #ahb3 changed infrared to infra-red 7,transparency of chitin to infra-red1 #eb7 ,page #ahb3 added missing page references 7,weiser1 ,h4 ,b41 #cc1 #cd1 #ci7