,illustration3 ,,ptychoptera ,,paludosa ,,limnobia ,,replicata ,from enlarged photographs1 made at the ,yorkshire ,college1 ,leeds1 from specimens bred by the ,author1 and mounted by ,messrs4 ,watson ,son1 ,high ,holborn1 ,london ,,through ,a ,,pocket ,,lens ,,by ,,henry ,,scherren1 ,f4,z4,s4 ,,author ,,of #8,,ponds ,,and ,,rock ,,pools1' #8,a ,,popular ,,history ,,of ,,animals1' ,,etc4 ,,with ,,ninety ,,illustrations ,,the ,,religious ,,tract ,,society #ef ,,paternoster ,,row ,,and #fe ,,st4 ,,paul',s ,,churchyard #ahig ,oxford ,,horace ,,hart1 ,,printer ,,to ,,the ,,university ,,contents ,,chapter ,i4 ,,page ,,the ,,pocket ,,lens1 ,,the ,,dissecting ,,microscope1 ,,and ,,some ,,simple ,,appliances #aa ,,chapter ,,ii4 ,,arthropods ,,and ,,their ,,classes4--,,the ,,margined ,,water ,,beetle2 ,,the ,,great ,,water ,,beetle2 ,,the ,,cocktail ,,beetle #bg ,,chapter ,,iii4 ,,cockroaches2 ,,earwigs2 ,,the ,,great ,,green ,,grasshopper2 ,,the ,,water ,,scorpion2 ,,the ,,water ,,boatman2 ,,corixa #fc ,,chapter ,,iv4 ,,spiders1 ,,mites1 ,,and ,,myriapods #if ,,chapter ,v4 ,,crustaceans4--,,prawn1 ,,shrimp1 ,,mysis1 ,,crabs2 ,,amphipods2 ,,isopods #abh ,,chapter ,,vi4 ,,aquatic ,,insect ,,larvae #aeg ,,index #ahi ,,list ,,of ,,illustrations ,,fig4 ,,page ,ptychoptera paludosa4 ,limnobia replicata ,frontispiece #a4 ,hand ,magnifier and ,stand #ad #b4 ,zeiss's ,dissecting ,microscope #af #c4 ,leitz's ,dissecting ,microscope #ag #d4 ,two ,leitz ,lenses in holder 7open7 #ah #e4 ,two ,leitz ,lenses in holder 7closed7 #ah #f4 ,home-made ,dissecting ,microscope #ai #g4 ,beakers #ba #h4 ,glass ,capsule #ba #i4 ,glass ,block1 with cover #bb #aj4 ,glass ,box1 with cover #bb #aa4 ,forceps #bc #ab4 ,three forms of ,dipping-tube4 ,method of using it #bd #ac4 ,mounted ,needles #be #ad4 ,cape ,peripatus 7natural size7 #cj #ae4 ,margined ,water ,beetle 7male7 #cb #af4 ,shells of ,molluscs broken up by ,dytiscus #cc #ag4 ,outline of ,dytiscus #ch #ah4 ,male ,dytiscus in flight #ci #ai4 ,to show fold of 7right7 wing of ,dytiscus #dj #bj4 ,to show fold of 7right7 wing of ,dytiscus #dj #ba and #ba ,a4 ,head of ,dytiscus #db #bb4 ,disposition of mouth parts #dc #bc4 ,leg of ,cockroach #dd #bd4 ,tarsus of ,dytiscus 7magnified7 #de #be4 ,female ,dytiscus swimming #df #bf4 ,upper surface of abdomen of typical ,beetle #dg #bg4 ,spiracle of ,dytiscus 7magnified7 #dh #bh4 ,tracheal tubes of ,dytiscus 7magnified7 #dh #bi4 ,great ,water ,beetle #ea #cj4 ,female ,hydrophilus constructing a cocoon4 7,after ,lyonnet7 #ee #ca4 ,cocktail ,beetle #eh #cb4 ,cockroaches #ff #cc4 ,mouth parts of a ,cockroach #fi #cd4 ,cockroach1 showing ,spiracles #ga #ce4 ,alimentary ,canal of ,cockroach #gc #cf4 ,american ,cockroach 7male7 #ge #cg4 ,larva and ,pupa of ,earwig #gg #ch4 ,earwig 7male7 #gh #ci4 ,great ,green ,grasshopper 7female7 #ha #dj4 ,tibial ear of ,great ,green ,grasshopper #he #da4 ,land ,bug 7magnified7 #hf #db4 ,water ,scorpion #hg #dc4 ,organs of ,water ,scorpion1 ,egg1 and ,parasitic ,mite4 7,after ,swammerdam7 #ij #dd4 ,raptorial leg of ,water ,scorpion #ib #de4 ,water ,boatman #ic #df4 ,water ,boatman swimming #id #dg4 ,corixa1 with wings expanded #ie #dh4 ,scheme of under surface of ,wolf ,spider 7female74 ,pedipalp of male 7enlarged7 #ih #di4 ,garden ,spider and ,web #ii #ej4 ,threads of ,spider's ,web #ajj #ea4 ,anchorage of ,web #aja #eb4 ,foot of ,garden ,spider #ajd #ec4 ,spinnerets of ,garden ,spider #ajd #ed4 ,jumping ,spider #ajf #ee4 ,falces of ,male ,jumping ,spider #ajf #ef4 ,foot of ,jumping ,spider4 ,scopula much enlarged #ajh #eg4 ,diving ,spiders #aji #eh4 ,cell of ,diving ,spider #aab #ei4 ,red ,water ,mite #aad #fj4 ,larva of ,water ,mite #aag #fa4 ,nymph of ,water ,mite #aag #fb4 ,beetle ,mite #aai #fc4 ,lithobius forficatus4 ,mouth parts seen from below4 7,after ,graber7 #abd #fd4 ,the ,common ,millepede #abf #fe4 ,segments of ,millepede 7magnified7 #abg #ff4 ,prawn #acb #fg4 ,first walking leg of ,shrimp 7enlarged7 #acd #fh4 ,mysis1 or the ,opossum ,shrimp #ace #fi4 ,maxillipedes and ,maxilla of ,shore ,crab4 7,after ,savigny7 #ach #gj4 ,stomach of ,crab laid open #aci #ga4 ,gammarus4 7,after ,sars7 #adb #gb4 ,maxillipedes of ,gammarus marinus 7magnified7 #adf #gc4 ,nest-building ,amphipod 7from life7 #adh #gd4 ,water ,woodlouse #aec #ge4 ,mouth-lock4 7,after ,burgess7 #afa #gf4 ,dytiscus ,larvae #afb #gg4 ,pupa of ,dytiscus #afd #gh4 ,larva of ,limnobia replicata #afg #gi4 ,forked spine of ,limnobia 7enlarged7 #afh #hj4 ,pupa case of ,limnobia #afi #ha4 ,fore wing of ,bee1 showing marginal fold 7#g7 #agj #hb4 ,larva of ,paraponyx stratiotata 7enlarged7 #agc #hc4 ,diagram of segment of ,paraponyx1 showing arrangement of tracheal gills #age #hd4 ,gill of ,paraponyx larva4 7,after ,de ,geer7 #agf #he4 ,larva of ,sialis 7enlarged7 #agi #hf4 ,diagram of ,sialis larva1 showing arrangement of gills #aha #hg4 ,pupa of ,sialis #aha #hh4 ,larvae of ,ptychoptera paludosa 7from life7 #ahd #hi4 ,ptychoptera ,larva 7enlarged74 ,tail4 7,after ,lyonnet7 #ahf #ij4 ,pupa of ,ptychoptera4 7,after ,lyonnet7 #ahg ,,through ,a ,,pocket ,,lens ,,chapter ,i ,,the ,,pocket ,,lens1 ,,the ,,dissecting ,,microscope1 ,,and ,,some ,,simple ,,appliances ,the object of this little book is to show how much may be seen with an ordinary pocket lens1 and with a simple microscope2 and1 as far as possible1 to dispel the idea1 far too common1 especially among beginners1 that no real work can be done unless one has a compound microscope1 with a large battery of lenses and an array of #8accessories4' ,it would be easy to multiply quotations1 from high authorities1 in support of the proposition implied in the foregoing paragraph4 ,two only must suffice4 ,in a recent review of a very good book dealing with ,butterflies and ,moths 7,natural ,science1 vol4 vi4 p4 #bic71 the following passage occurs3 #8,the only suggestion we should like to make is that a compound microscope is unnecessary for any of the details that the author mentions4 ,a first-rate platyscopic hand lens is much more convenient and the young naturalist should train himself thoroughly in the use of it4 ,there is no more common error than the undue use of the higher powers of a microscope4 ,except for the intimate details of histology1 a low power or a hand lens is much more easy to use1 and its employment gives a much better idea of the structure4' ,the next quotation is of greater interest1 as it gives some insight into the way in which ,darwin carried on his investigations4 ,in the ,life and ,letters of ,charles ,darwin 7vol4 i4 pp4 #ade1 #adf7 we are told3 #8,his natural tendency was to use simple methods and few instruments4 ,the use of the compound microscope has much increased since his youth1 and this at the expense of the simple one4 ,it strikes us nowadays as extraordinary that he should have had no compound microscope when he went his ,beagle voyage2 but in this he followed the advice of ,robert ,brown1 who was an authority in such matters4 ,he always had a great liking for the simple microscope1 and maintained that nowadays it was too much neglected1 and that one ought always to see as much as possible with the simple before taking to the compound microscope4 ,in one of his letters he speaks on this point1 and remarks that he always suspects the work of a man who never uses the simple microscope4' ,it may be well here to verify the quotations1 and also to consult ,darwin's ,naturalist's ,voyage1 to ascertain what kind of objects he examined with the simple appliances at his command4 ,in the first chapter there is an interesting account of a curious limy deposit on the rocks of the island of ,st4 ,paul's1 and of the discoloration by confervae of the water1 which1 #8under a weak lens1 seemed as if covered by chopped bits of hay1 with their ends jagged4' ,then we have an account of the confervae in the ,indian ,ocean1 and of infusoria so numerous as to tinge the water off the coast of ,chile4 ,in the second chapter we have observations and experiments on planarian worms4 #8,having cut one of them transversely into two nearly equal parts1 in the course of a fortnight both had the shape of perfect animals4' ,in the next chapter he records some observations on the structure of vitrified tubes formed by lightning striking loose sand4 ,in the fifth chapter is an elaborate description of a kind of sea-pen2 and in the ninth chapter there are some remarks on the vast number of eggs in the egg-ribbon of a sea-slug1 and on the #8bird's-head' organs in certain ,polyzoa4 ,these remarks were1 of course1 founded on actual inspection with the simple microscope4 ,to this instrument1 also1 we owe the discovery of the tadpole-like larvae of ,ascidians1 or ,tunicates1 as they are now generally called4 #8,at the ,falkland ,islands ,i had the satisfaction of seeing1 in ,april1 #ahcc1 and therefore some years before any other naturalist1 the locomotive larvae of a compound ascidian4444 ,the tail was about five times as long as the oblong head1 and terminated in a very fine filament4 ,it was1 as sketched by me under a simple microscope1 plainly divided by transverse opaque partitions1 which ,i presume represent the great cells figured by ,kovalevsky4 ,at an early stage of development the tail was closely coiled round the head of the larva#a4' 99 99 99 99 99 ,we come now to our pocket lens1 which may be purchased for a few shillings of any optician4 ,one can buy a serviceable single lens1 in an ebonite handle1 for a shilling2 and this cheap instrument is sufficiently powerful not only to give the worker a good general idea of the form and structure of objects1 but to enable him to do real work4 ,with it the habits of many of the inmates of his aquaria may conveniently be watched2 he may see their development from stage to stage of their life-history2 and with it1 when they are broken up1 he may make out a good deal of their external and internal anatomy4 ,illustration3 ,,fig4 #a4--;,hand ,magnifier and ,stand4 ,a very good form is shown at ,fig4 #a1 which represents a hand magnifier1 fitted with three lenses of different focus1 generally #b in41 #a in41 and #a in4 ,examination of the catalogues of the principal ,london opticians shows that such a set of lenses may be bought for about #cs4 ,in shape and construction there is sometimes a little variation2 but the form figured is that most generally adopted1 and is1 on the whole1 fairly convenient4 ,it would1 however1 be an advantage if the hole by which the magnifier is mounted on the stand were drilled in the solid part of the handle4 ,this would not only do away with the objection that the hole in the case permits dust to penetrate to the glasses1 when carried in the pocket1 but would give a longer reach1 and thus obviate the necessity for moving the stand if the observer were examining a large object4 ,the price of the stand figured is #bs4 #f;d42 and one with a short adjusting arm ought not to cost much more4 ,any one with a mechanical turn may make a stand for himself1 though it may be doubted whether this is quite worth while when these articles may be bought so cheaply4 ,nevertheless1 there is great pleasure in making things for oneself2 and a home-made stand will enable the observer to do quite as good work as one that came from the optician's shop4 ,a bill-file weighted at the foot may be bought for a few pence1 and adapted to the purpose4 ,for the slider a large cork cleanly pierced will answer admirably4 ,this should carry a piece of stout wire1 bent at the end thus image1 to serve as a holder for the magnifier1 which should have a hole in the handle1 for the reasons stated above4 ,the only difficulty will be the attachment of the wire to the cork4 ,the ,rev4 ,j4 ,g4 ,wood advocated winding the wire round the cork in a spiral2 and this is a very good plan4 ,an increase of steadiness is secured1 if a larger cork1 or small bung1 be used1 and the wire inserted in the side4 ,there are1 of course1 more expensive lenses1 with which better definition can be obtained4 ,zeiss has an excellent magnifier consisting of two lenses1 for use in the dissecting microscope 7,fig4 #b71 and also as a hand lens1 at the price of #fs42 one of the same construction1 for use in the dissecting microscope alone1 may be had for #ds4 ,the ,steinheil achromatic lenses are probably the best of all4 ,these are made in powers ranging from #b in4 to in4 focus#b2 and the price varies from #ajs4 up to #a1 according to the maker4 ,those made by ,leitz of ,wetzlar cannot be surpassed2 and they are sold in ,london at #ajs4 each1 either mounted in a handle1 for use as hand magnifiers1 or with a collar for use in ,leitz's dissecting microscope 7,fig4 #c74 ,mr4 ,lewis ,wright says that #8the best plan is to combine both uses1 and have two or three powers in collars1 with a spring ring folding into a handle1 which will carry any one of them in that manner4 ,a ,steinheil lens at this low price costs little more than a ,coddington1 while its performance is infinitely superior#c4' ,it is a difficult thing to get makers to deviate from the beaten track1 and so far as ,i have been able to learn1 ,mr4 ,wright's wishes have not been fulfilled4 ,illustration3 ,,fig4 #b4--,zeiss's ,dissecting ,microscope4 ,the lenses and stand 7,fig4 #a7 constitute a simple form of dissecting microscope4 ,if the worker wishes for something more elaborate1 he need only consult the catalogues of the principal makers to find something that will meet his requirements4 ,zeiss's brass stand1 with stage1 above which a lens slides up and down in a holder 7,fig4 #b71 is sold for #is42 with blocks for supporting the hands1 at #ajs4 ,it is a useful instrument for small objects4 ,my favourite instrument is shown at ,fig4 #c4 ,here the focussing of the lens is effected by rack and pinion work1 by means of the screws on each side the upright pillar4 ,the lens is shown fitted in the collar which carries it4 ,the stage is of glass--roughly1 #b in4 long by #b in4 wide1 and the arm at the top of the pillar can be moved from side to side1 so as to bring a fairly large object within range4 ,the metal framework of the stage is furnished with nickelled clips 7not shown71 which serve to hold an excavated slip4 ,the arm-rests are detachable1 and the uprights are hinged for convenience of packing4 ,the instrument 7with the exception of these rests7 packs into a neat1 strong mahogany box1 #g in4 in length1 and about #e in4 in height and width4 ,with two powers--#a in4 and in4 are very serviceable ones--the cost is #chs4 ,illustration3 ,,fig4 #c4--,leitz's ,dissecting ,microscope4 ,it is to be wished that the maker would devise some plan by which the admirable lenses sold with this instrument could be utilized for the pocket4 ,mr4 ,c4 ,curties1 of ,baker ,co41 ,high ,holborn1 has kindly done something in the matter1 and has made for me a metal holder4 ,i have found this convenient1 but should be glad to see something further done in the same direction1 so that instrument1 lenses1 and holder could be sold for #b4 ,this ought to be within the range of practical optics4 ,the spring collar advocated by my friend ,mr4 ,wright seems better1 and would certainly be cheaper4 ,the lenses would only need to be dropped in4 ,to use my pocket holder one must unscrew the metal collar from the lenses before screwing them into the metal plates which carry them 7,fig4 #d74 ,it is1 however1 something to have made a beginning3 it is a step in the right direction4 ,illustration3 ,,fig4 #d4--,two ,leitz ,lenses in holder 7open74 ,illustration3 ,,fig4 #e4--,two ,leitz ,lenses in holder 7closed74 ,a serviceable dissecting microscope--not a toy1 but an instrument with which real work may be done--can be made at a cost of a few shillings4 ,such a one has been made for me by a friend with a positive genius for such work4 ,the body is fashioned out of a parcel-post box #g in4 long1 #c in4 in height1 and the same in width4 ,from the centre of the sliding top a piece is cut away1 leaving ledges to take a #c in4 by #a in4 excavated slip for small dissections1 or a mounted slide of a large object1 such as a whole insect1 for examination4 ,a further portion is cut away on each side to take a small dissecting dish 7,fig4 #f74 ,to admit the light1 a hole is cut in the side of the box2 and the mirror consists of a piece of silvered glass which was bought of a hawker in the street4 ,this is placed in the box opposite the square hole1 and sloped at an angle of #de4 ,the aid of a skilled mechanic was sought for a small rod carrying a thread1 which works in a piece of brass bent at a right angle4 ,this piece of brass is screwed on the box1 just above the aperture by which light is admitted1 and carries a pocket magnifier1 similar to that shown at ,fig4 #a4 ,illustration3 ,,fig4 #f4--;,home-made ,dissecting ,microscope4 ,this modest little instrument generally stands on my work-table1 and has provoked some remark and a little good-natured banter from friends who have seen it4 ,nevertheless1 ,i should be sorry to part with it1 for ,i have found it extremely serviceable in many ways4 ,and more than one critic has had to confess that better results were obtained than one would expect from its appearance4 ,the total cost out of pocket was1 #c;d4 for the box1 #cs4 for the lens1 and #a;d4 for the plate-glass1 while the man who made the pillar and ear-piece would take no more than #f;d4 for his work4 ,this brings the total to #cs4 #aj;d4 ,with a little ingenuity the pillar might be made to carry a collar1 and so take a ,steinheil lens4 ,this would swell the total cost to about #aas4 ,other apparatus need not be costly4 ,an incident occurred at the meeting of the ,quekett ,microscopical ,club on ,november #bb1 #ahgh1 which shows how readily common objects may be utilized for our purpose4 ,the late ,right ,hon4 ,t4 ,h4 ,huxley1 who was at that time ,president1 exhibited1 and made some remarks on1 the dissecting microscope which now bears his name4 ,during the discussion which followed1 ,professor ,charles ,stewart exhibited some little saucers1 which were admirably adapted for dissecting purposes4 ,the ,president said that he should #8be glad to know where these convenient little saucers could be obtained4' ,the next paragraph of the minutes is interesting and instructive4 #8,mr4 ,stewart said they were to be found at the corners of the streets1 containing three whelks or three mussels for a penny4 ,he bought those he had brought to the meeting at a shop in the ,new ,cut1 where they were supplied to costermongers#d4' ,as very many of the objects with which we are concerned are aquatic1 we shall want vessels of some sort to serve as aquaria4 ,any glass vessel will answer our purpose1 provided it is clear1 to allow of the examination of our captives2 or shallow pie-dishes may be utilized4 ,the glass pots in which preserves are sold will do admirably1 and any glazier will cut us covers for a few pence4 ,within reasonable limits1 the smaller the aquaria are the better4 ,the inmates can be seen more easily1 and picked out with less trouble when one wishes to examine them4 ,the principles on which aquaria should be kept are now pretty generally understood4 ,there should always be a small quantity of growing aquatic vegetation1 and a supply of minute life to furnish food for the larger forms4 ,excess of light should be avoided1 and the temperature should not be allowed to rise much above #ej ,f4 ,carnivorous beetles and their larvae may be fed with small pieces of meat1 small garden worms1 or tadpoles4 ,most of the smaller larvae treated of will be satisfied with vegetarian diet1 varied with an occasional meal of water-fleas4 ,illustration3 ,,fig4 #g4--;,beakers4 ,illustration3 ,,fig4 #h4--;,glass ,capsule4 ,if one cannot lay the household stores under contribution for jam-pots1 tumblers1 and bottles1 beakers 7,fig4 #g7 make capital small aquaria4 ,they are sold in nests1 and may be had either rimmed or lipped--rimmed for choice4 ,there is no difficulty in obtaining them of any optician or glass-merchant4 ,mine have been bought from ,messrs4 ,beck1 of ,cornhill1 as have the capsules1 c41 figured here4 ,glass capsules 7,fig4 #h7 are made in different sizes1 ranging from #a in4 to #c in4 in diameter1 with a height of #a in4 or #b in4 ,the largest size1 #c in4 by #b in41 costs #e;d41 and a glass circle to cover it1 #a;d4 ,these capsules will be found useful for small aquaria1 and for isolating aquatic larvae in order to keep them under observation during their change to perfect insects4 ,it was in a capsule of this kind that some of my ,ptychoptera larvae 7p4 #ahd7 were kept1 and changed into the pupal condition4 ,the glass block1 with cover 7,fig4 #i71 is convenient for a number of purposes4 ,in it small creatures may be examined in air or in water1 and it makes an exceedingly convenient little dissecting dish for use with the mounted hand magnifier 7,fig4 #a71 or with ,leitz's stand 7,fig4 #c71 or the home-made stand 7,fig4 #f74 ,the glass box1 with cover 7,fig4 #aj71 is extremely good for keeping small creatures under observation4 ,illustration3 ,,fig4 #i4--;,glass ,block1 with cover4 ,illustration3 ,,fig4 #aj4--;,glass ,box1 with cover4 ,excavated glass slips1 #c in4 by #a in41 may be bought from any optician4 ,they serve for the examination of objects in water1 and also for dissection4 ,the best ,i have been able to get have been supplied by ,mr4 ,j4 ,hornell1 of the ,biological ,laboratory1 ,jersey1 and they are very cheap4 ,we shall need some forceps to pick up specimens from the vessels in which they are kept1 and the same little instruments will be found convenient in collecting4 ,both forms have advantages of their own2 if we are limited to one pair1 they should be curved1 and of brass4 ,forceps with ivory tips are very useful for handling aquatic vegetation4 ,these articles are not usually sold by opticians1 but are kept by the tradesmen in ,clerkenwell who sell jewellers' and watchmakers' tools1 and cost from #as4 to #as4 #f;d4 a pair4 ,illustration3 ,,fig4 #aa4--;,forceps4 ,dipping-tubes are used to take up small aquatic animals from the vessels in which they are kept4 ,very little practice will render the use of this instrument easy4 ,the tube is held firmly between the thumb and the third and fourth fingers of either hand1 while the index finger is pressed firmly on the top4 ,most people naturally prefer the right hand1 but it is well to accustom oneself to use the right or left indifferently4 ,the open end is then put into the water1 just over the object to be secured1 and the index finger lifted4 ,the rush of water into the tube will carry the object into it1 and if the finger be again applied to the top1 the pressure of the atmosphere will prevent the water from escaping when the tube is lifted out#e4 ,small brushes are useful for taking up specimens from the water or from pickle2 common ones will do very well for large objects1 but for small objects and parts it is advisable to have one or two sable brushes1 as these form a better point4 ,some needles fixed in handles will also be necessary4 ,these may be bought1 or made by fixing ordinary needles of requisite sizes into the handles sold for small brushes4 ,the needles must be kept free from rust1 and should always be carefully wiped after use4 ,a good plan to keep them clean is to stick them in a gallipot in which has been melted a mixture of lard and paraffin in equal proportions4 ,small dissecting-knives are useful1 but all the work described here may be done with an ordinary pocket-knife in good trim4 ,illustration3 ,,fig4 #ab4--,three forms of ,dipping-tube4 ,method of using it4 ,the best preservative for our purpose is formalin1 which is sold in a forty per cent4 solution4 ,this should be treated as absolute1 and a five per cent4 solution made4 ,this will really be a two per cent4 solution1 and is sufficiently strong for general use4 ,the most profitable use we can make of specimens is to watch their habits while living1 and to break them up and learn as much as we can about their structure when they are dead4 ,for us to make a collection of specimens in tubes would be a waste of material4 ,illustration3 ,,fig4 #ac4--,mounted ,needles4 ,little need be said about collecting4 ,the objects treated of are so plentiful that no great skill1 nor any wealth of appliances1 is needed to secure an ample supply4 ,the following remarks on the methods employed at the ,illinois ,state ,laboratory for the capture of aquatic insects and larvae are1 however1 worth quoting3-- #8,insects in vegetation1 and on or in the bottom1 were taken by means of a dip-net--a net of about equal depth and width attached to a strong semicircular ring1 firmly fixed to a long handle1 the straight side of the ring being opposite the point of attachment4 ,for the larger and more active forms1 a coarser net was used1 and for smaller forms one made of finer net proved most durable and satisfactory4 ,to collect from the mud of the bottom1 the water immediately over it was violently stirred and then swept with the net4 ,the surface layer of mud was also scooped up in the fine dip-net1 and then allowed to wash through1 leaving the coarser contents in the net4 ,insects on the bottom in deep water were secured by using a dredge1 and washing its contents through net sieves4 ,the aquatic vegetation1 when free from mud1 was violently washed in a large pan1 many smaller forms being thus dislodged and coming to the surface4 ,insects occurring in open water were taken in drawing an ordinary towing-net#f4' ,here we have1 so to speak1 the general principles of collecting4 ,it will be easy to adapt them to particular cases4 ,in choosing the subjects to be treated of in this little book1 some difficulty has been experienced in deciding what to select from the multitude that lay ready to hand4 ,it was felt necessary that the subjects should be connected1 since choosing them at random would lead to purposeless work1 and so to waste of time and opportunity4 ,after some consideration1 the author has decided to take all the examples from the ,arthropoda--that great sub-kingdom of backboneless animals which includes the ,lobster1 the ,crab1 the ,sand-hopper and the ,woodlouse1 the ,spider and the ,mite1 the whole world of ,insects and the ,centipedes4 ,one cogent reason that influenced this decision was the fact that these objects are exceedingly common1 so that there can be no difficulty in procuring material on which to work4 ,there is1 perhaps1 no other sub-kingdom so full of interest1 on account of the many widely different forms1 which may be referred to one common plan4 ,it may possibly appear to some readers that the powers of the pocket lens have been exaggerated4 ,as a matter of fact the material for the book has been gathered by actual observation4 ,the author has seen1 with an ordinary pocket lens1 the objects here described4 ,if some are shown as they would appear under greater magnification than such a lens would give1 this is chiefly for the sake of emphasizing points of interest which might otherwise be overlooked1 but which can readily be made out with a hand magnifier1 when attention has been drawn to them1 and the observer knows what to look for4 ,,chapter ,,ii ,,arthropods ,,and ,,their ,,classes4--,,the ,,margined ,,water ,,beetle2 ,,the ,,great ,,water ,,beetle2 ,,the ,,cocktail ,,beetle ,having got together our apparatus1 which1 as we have seen1 need be neither costly nor complicated1 the next step will be to acquire some knowledge of the group from which the examples here treated of will be taken--the ,arthropods1 or animals with hollow-jointed limbs4 ,these are the #8,insects' of the ,linnaean classification1 and1 for the matter of that1 of popular phraseology2 for though few people would now venture to call a ,lobster an #8insect1' we still style some of its near relatives ,water #8,fleas1' as ,swammerdam did two hundred years ago4 ,the ,arthropods form a phylum1 or main division of the ,animal ,kingdom4 ,above this phylum comes that of the ,molluscs1 or soft-bodied animals1 such as the ,oyster1 the ,snail1 and the ,cuttlefish4 ,still higher are the ,lancelet1 the ,sea-squirts1 and some few others1 that bridge the chasm between the phyla without1 and that phylum with1 a backbone4 ,and to this last ,man himself belongs4 ,two reasons contributed to the selection of the ,arthropods as a subject for work with the pocket lens3 7#a7 the great interest which surrounds many of the group2 and 7#b7 the ease with which specimens may be procured and kept under observation4 ,every one has pretty clear notions as to the general #8make' of a ,vertebrate or backboned animal4 ,an ,invertebrate animal has1 of course1 no backbone or the semblance of one2 the nervecord1 where present1 lies on the under surface1 and forms a ring round the gullet1 and the heart lies on the upper surface or back4 ,we may verify this by pulling to pieces a dead insect4 ,but a phylum1 or main division1 is much too large to be considered as a whole4 ,it must1 therefore1 be broken up into smaller groups1 which are called ,classes1 generally reckoned as five in number4 ,these1 again1 may be grouped into two divisions1 according as their members breathe by means of air-tubes 7tracheae7 or by gills4 ,our scheme then will stand thus3-- ,peripatus4 ,breathing by ,centipedes and ,millipedes4 air-tubes ,insects4 ,,arthropods ,spiders and their kin4 ,breathing by ,lobsters1 ,crabs1 ,sand-hoppers1 gills and ,woodlice4 ,this scheme looks well on paper2 and on the whole is workable4 ,but among our examples chosen from the ,class of ,insects1 we shall find some that breathe by gills in their larval stage1 and by air-tubes when adult4 ,and among the ,crabs are some1 the gills of which have ceased to perform their normal function1 so that these animals cannot live in water for a single day4 ,and then there are the ,sand-hoppers and ,woodlice4 ,the body of an ,arthropod may be represented by a series of similar rings1 thus3 ,illustration ,this similarity is clearly apparent in the ,centipede1 but is concealed in the ,beetle1 the ,shrimp1 and the ,spider4 ,it seems1 at first sight1 to be altogether lost in the ,crab1 and does really vanish in the adult stage of some parasitic ,crustaceans4 ,it may be plausibly objected that our ideal ,arthropod resembles nothing so much as a worm4 ,in many respects this is true4 ,a primitive ,arthropod was worm-like1 as is a ,centipede4 ,and ,arthropods and ,worms were formerly classed together in one group1 as ,annulosa or ringed animals4 ,the chief external difference lies in the nature of the appendages borne by the various rings or segments4 ,we may represent those of the ,worms thus image1 for they are bristles1 or groups1 or modifications of bristles4 ,those of the ,arthropods may be represented thus image1 for the appendages are really jointed1 though1 of course1 in a fashion different from those of a backboned animal4 ,the jointed appendages of ,arthropods may be modified to fulfil very different functions4 ,they may serve as legs for walking1 hands for climbing or seizing prey1 jaws for masticating food1 feelers or organs of touch and sense1 and1 strange as it may seem1 in one group1 as eyes4 ,it is well to get some notion of how these joints are formed4 ,to take the body first3 the skin connecting the segments is much thinner than that of the segments themselves1 which is thickened by the deposition of chitine1 and1 in some cases1 also of carbonate and phosphate of lime4 ,a portion of the body1 then1 may be represented thus1 image where the heavy lines denote the segments1 and the thin ones the spaces between the segments4 ,it will be seen that this arrangement allows of considerable play1 and also of a telescopic movement by which the segments can be brought close together4 ,it is easy to construct a kind of model that shall exemplify these movements4 ,make a tube of calico1 some six inches long1 and having stuffed it with cotton-wool1 paste on it strips of brown paper one inch in width1 leaving an interval between each1 as in the last diagram4 ,then we shall be able to understand how ,arthropods can bend the body or move it from side to side4 ,and the limb joints are made on a similar plan4 ,illustration3 ,,fig4 #ad4--;,cape ,peripatus 7natural size74 ,the most archaic ,arthropod--,peripatus--must be mentioned4 ,it is not found in ,britain1 nor even in ,europe2 so that1 unless we travel1 we shall only know it from books1 or from museum specimens4 ,but it is an extremely interesting creature1 for it is of worm-like aspect1 and breathes by air-tubes1 opening all over the body1 which has no external segments4 ,the limbs are imperfectly jointed1 and each of them bears two claws4 ,most naturalists make this genus a ,class by itself1 while some put it with the ,centipedes4 ,there are about a dozen species1 four of which are ,african1 two ,australian1 and the rest are found in ,south ,america and the ,west ,indies4 ,besides these there are some doubtful species4 ,in habit they resemble the ,centipedes1 and they ensnare the insects on which they feed by ejecting sticky slime from the small processes near the mouth4 ,the left process is shown in the illustration1 just below the antenna of that side4 ,professor ,sedgwick1 who described these animals in the ,quarterly ,journal of ,microscopical ,science 7#ahhh71 and1 more popularly1 in the ,cambridge ,natural ,history1 says1 that #8the exquisite sensitiveness and changing form of the antennae1 the well-rounded plump body1 the eyes set like small diamonds on the side of the head1 the delicate feet1 and1 above all1 the rich colouring and velvety texture of the skin1 all combine to give these animals an aspect of quite exceptional beauty4' ,unfortunately1 an illustration in black-and-white can only render form4 ,we must take the beauty of the colouring for granted4 ,one thing1 however1 cannot escape the most cursory examination of the picture--the resemblance of the creature1 in some respects1 to a worm1 and1 in others1 to a caterpillar1 which1 as everybody knows1 is the larval stage of a butterfly4 ,if this resemblance sets us thinking how it came about1 and what it means1 ,peripatus will1 for the present1 have done its work for us4 99 99 99 99 99 ,with these general notions of ,arthropods1 we may pass on to put our pocket lens to some practical use4 ,our first subject shall be the ,margined ,water ,beetle 7,dytiscus marginalis71 which can be taken in almost any open pond in the country4 ,water covered with duckweed should be avoided in hunting for these beetles1 which prefer ponds with a clear surface1 so that they may easily come to the top to breathe4 ,every one has a good general notion of the principal ,insect-groups1 technically called ,orders--,beetles1 ,cockroaches and ,grasshoppers1 ,butterflies1 ,bees and ,wasps1 and ,flies4 ,insects may be defined as animals with hollow-jointed limbs1 and divided into three regions--head1 thorax1 and abdomen4 ,the head bears a pair of antennae2 the thorax carries three pairs of legs1 and 7generally7 two pairs of wings2 the abdomen is without appendages4 ,insects when adult breathe by tubes that open to admit air4 ,in ,chapter ,,vi we shall see that many larvae obtain an air supply in different ways4 ,illustration3 ,,fig4 #ae4--,margined ,water ,beetle 7male74 ,beetles may be taken as very good types of true ,insects4 ,they constitute the ,order ,coleoptera1 or ,insects with sheathed wings1 only the hinder pair being used for flight 7,fig4 #ah71 and at other times they are folded under the wing-cases1 or elytra1 as in ,fig4 #ae4 ,we may advantageously compare our ,beetle with ,peripatus1 and note the points of agreement and of difference4 ,now1 if our captive ,beetles are to yield us the greatest possible amount of profit1 we shall keep them under observation for some time1 so as to watch their habits4 ,in keeping these ,beetles we shall not require a large aquarium4 ,a small gathering of aquatic weed will be necessary to keep the water in good condition and the aquarium ready for its tenants4 ,my interest in these ,beetles was quickened by a letter in the ,field 7,oct4 #bh1 #ahic71 in which a correspondent at ,weybridge asked #8for information as to what animal or bird bisects so neatly the shells of the ,water ,snail 7,planorbis74' ,i thought then1 and know now1 that the shells were #8bisected1' if that is the proper word1 by ,water ,beetles4 ,from that time ,i have had1 and still have1 several living in small aquaria1 but for a long time was unable to get direct evidence on the subject4 ,illustration3 ,,fig4 #af4--,shells of ,molluscs broken up by ,dytiscus4 7,from a photograph by ,cherry ,kearton47 ,many experiments were tried1 and at last these proved successful4 ,several specimens of ,dytiscus#g were obtained1 and put into a small aquarium in which was no other food for them than some snails and other molluscs4 ,the ,beetles were carefully watched1 and were several times seen trying the snails4 ,in crawling along the inner surface of the glass1 ,planorbis and ,limnaea both protrude the foot to a considerable extent1 and pieces were ripped out by the strong mandibles of the ,beetles before the shells were actually broken up4 ,all the shells represented in ,fig4 #af were taken from this aquarium1 so that there is good evidence as to what creatures broke them up and devoured their inmates4 ,in these1 as in the specimen kindly sent me by ,mr4 ,tegetmeier1 the ,natural ,history ,editor of the ,field1 the bisection is not complete1 though in all cases it is carried far enough to allow of the extraction of the mollusc4 ,the large ,limnaea shell in the centre has been attacked1 but it seems to have been left when the beetles discovered it was empty4 7,the empty shell was noted before the ,beetles were put into the tank47 ,another ,limnaea shell is figured1 from which the snail has been picked out1 and that of a fresh-water mollusc4 ,after these observations had been recorded in the ,field#h1 ,i found that ,i had been anticipated by about forty years4 ,i picked up1 at a bookstall1 a copy of ,g4 ,b4 ,sowerby's ,popular ,history of the ,aquarium1 and there ,i found that the author had distinctly seen ,dytiscus at this kind of work4 ,he says#i3 #8,i have only once witnessed him in the act of seizing an unfortunate ,planorbis or ,flat-coiled ,water ,snail4 ,at first1 the ,dytiscus seemed to be roaming about in quest of something1 first under1 then over1 the leaves of a water-lily4 ,at last1 in a rather dark corner1 he seemed to perceive suddenly a ,planorbis which was browsing upon the stem of a plant just under the shade of a broad leaf4 ,he darted at this1 seized it1 and then1 putting his tail out of water1 for the purpose of taking in a fresh supply of air1 moved slowly down1 bearing the snail with him4 ,he held it by his fore-feet1 turning round the coil until the aperture of the shell was opposite his mandibles1 then he began nibbling away at the animal4 ,in vain did the poor mollusc try to withdraw within its shelly fortress1 for the beetle picked off the edges of the shell bit by bit1 so as to expose the body as fast as it was withdrawn4 ,all the way down to the bottom of the tank was this process continued1 air-bubbles rising to the top1 and bits of broken shell falling1 till the beetle with his burden reached a stone near the bottom1 where ,i left him still busy at his work4' ,this puts the matter beyond doubt1 if any before existed4 ,i at once wrote to ,mr4 ,tegetmeier to let him know that my experiments had1 unknown to me1 been anticipated1 long ago1 by ,mr4 ,sowerby4 ,had he rescued his ,planorbis shell1 it would have compared very well with those forwarded to the ,field office in #ahic4 ,they had been exhibited at the ,malacological ,society1 and no one was able to solve the mystery of their mutilation4 ,this shows1 to quote the ,field#aj on the subject1 #8how easily statements that have been recorded may subsequently be overlooked and entirely forgotten4' ,to return to our ,beetle4 ,the male is a handsome creature1 from an inch to an inch and a quarter long1 clad in olive-green1 bordered with yellow1 and exceedingly active4 ,his mate is smaller1 more soberly clad in brown1 without the yellow markings1 and the wing-cases are more or less furrowed4 ,the first thing to notice is the shape of the body1 oval and smooth1 offering no resistance to the water4 ,the hind pair of legs are flattened and fringed with hairs1 so as to make capital paddles4 ,in swimming the right and left legs are moved together4 ,now1 though this ,beetle lives in the water1 it is made1 so far as concerns its breathing apparatus1 after the fashion of a ,land ,beetle1 and consequently is compelled to come to the surface pretty frequently for a supply of air1 which it obtains in this wise4 ,directly it ceases paddling it floats to the top of the water2 and as the head is heavier than the tail the latter projects a little above the surface4 ,then the wing-cases are raised1 and air flows in under them to the breathing holes on each side4 ,the operation is not a long one1 and as soon as it is over the ,beetle is ready for another ramble round his dwelling-house4 ,but if we do not supply our captive with food that he may take for himself1 it is only right that we should feed him1 which may be done at intervals--say1 every other day4 #8,little1 and often1' is an excellent motto to guide us in our feeding2 and though its adoption may entail some trouble1 it will be more than compensated by the success that will attend our endeavours to keep the inmates of our aquarium in good condition4 ,and the operation of feeding our ,beetle will show us that he has some capital sense-organs1 which are of as much1 if not of more1 use to him than his eyes4 ,he is a flesh-eater4 ,let us take a small piece of meat or fish in a pair of forceps1 or stuck on a pointed stick1 and hold it at a little distance from his great eyes4 ,the chances are that he will not see it4 ,even if we put it in front of him1 he is quite likely to disregard it1 for he has nothing corresponding to a nose1 with which he may smell4 ,from his head there spring a pair of long feelers--the antennae--and by means of these we will let him know that his dinner is ready4 ,that is effected by drawing the food along the side of one of the antennae4 ,the creature undergoes a sudden change4 ,till the antenna was touched with the food he was resting on his swimming legs4 ,but in a moment down goes his tail and up goes his head1 he stretches out his raptorial legs1 and clutches wildly at the forceps or stick1 as the case may be1 holding so tight that he may be dragged round and round the glass vessel4 ,let go he will not1 of his own accord2 and it would be a difficult matter to shake him off4 ,similar experiments may be tried with other ,beetles1 and the result will be to impress on the mind the fact that the feelers are capital sense-organs4 ,if we are to turn our ,beetle to the best account1 we shall need to handle him4 ,it may be inconvenient to wait till he dies1 so we will kill him quickly and painlessly by plunging him into boiling water1 and he may be preserved by putting him into a tube containing about equal parts of water and spirit1 or a five per cent4 solution of formalin4 ,dissections should properly be made under water4 ,the ,beetle should be fastened1 back upwards1 to a piece of cork weighted with lead1 and placed in a deep saucer1 or dissecting dish1 and covered with water4 ,but a good deal of rough dissection1 as is ours1 may be done in air1 and the ,beetle may be fastened to any convenient piece of board1 or even held in the palm of the left hand4 ,very little practice is needed to run over the external parts of a large ,beetle in this manner4 ,illustration3 ,,fig4 #ag4--,outline of ,dytiscus 7male74 a1 antenna2 b1 maxillary palp2 c1 eye2 d1 fore-leg2 e1 thorax2 f1 middle leg2 g1 elytron2 h1 suture2 i1 hind leg2 j1 claw2 k1 tarsus or foot2 l1 tibia or shank2 m1 femur or thigh2 n1 first three joints of foot1 widened into a plate with suckers beneath4 ,first1 let us look over our ,beetle1 and get some general notions of its make4 ,as it lies1 back upwards1 it is clear that it consists of three parts or regions------------image1 the first of which is the head1 the second the thorax1 and the third the abdomen4 ,not only in our ,beetle1 but in ,insects generally1 these parts correspond to the words that denote them1 in that the thorax is longer than the head1 and the abdomen longer than the thorax1 as shown by the three dashes1 a few lines above4 ,these divisions are well shown in ,fig4 #ag1 where other parts are also marked4 ,it will pay to go over our own specimen with this figure before us1 and so make acquaintance with the several parts1 to some of which we shall return in greater detail4 ,illustration3 ,,fig4 #ah4--,male ,dytiscus in flight4 ,at this point1 if we have not done so before1 it will be convenient to fasten our ,beetle1 in the position figured1 by a stout pin driven between the thorax and the abdomen1 just above the suture 7h74 ,we want to raise one of the wing-cases4 ,if a needle be taken in each hand1 between the thumb and first two fingers1 and that in the left hand be used to steady the creature1 the wing-case on the right may be raised with the needle in the right hand1 and then cut off4 ,the small filmy membrane1 of somewhat triangular shape1 which comes off with the wing-case1 is the winglet4 ,there is one on each side2 and their vibration causes the humming noise made by these insects in flight4 ,when the water dries up in one pond1 or food becomes scarce1 they will leave and fly off to another4 ,the wing lies folded upon the abdomen4 ,a good deal of very interesting matter has been written on the way in which ,insects fold their wings1 but we can see for ourselves how this ,beetle folds them4 ,all we have to do is to take the wing1 and draw it gently away from us1 and so unfold it4 ,we may use finger and thumb1 or a small pair of forceps4 ,when let go1 it will spring back to its old position4 ,reference to the expanded wing in ,fig4 #ah1 and to the diagrams ,figs4 #ai and #bj1 will show how the wing is folded4 ,illustration3 ,,fig4 #ai4--,to show fold of 7right7 wing of ,dytiscus4 ,illustration3 ,,fig4 #bj4--,to show fold of 7right7 wing of ,dytiscus4 ,the cross-mark in the diagram represents a joint in the chitinous rod that forms the wings4 ,this lies just above the cell 7which is left white in ,fig4 #ah74 ,the shorter part of the rod is bent down1 forming an acute angle 7,fig4 #bj72 of course1 carrying with it the membranous part of the wing4 ,this may seem a little difficult4 ,but if it be tried on a specimen1 no real difficulty will be experienced4 ,when the wing has been unfolded1 it will1 if let go1 spring back to its old position1 the shorter part lying underneath1 and the chitinous rod fitting into a groove formed by the projecting sides of the segments of the abdomen4 ,to this point the sum of our knowledge about ,dytiscus amounts to this3 ,it is aquatic in habits2 its body is divided into three regions2 and it has a pair of membranous wings1 covered by chitinous wing-cases1 or sheaths1 technically called elytra 7each being an elytron74 ,wing-cases of this kind are the distinguishing mark of the ,beetles1 or ,coleoptera1 though they are not always so well developed as in the specimen with which we are dealing4 ,this we can discover for ourselves by examining all the ,land ,beetles met with in a country ramble or in a stroll round the garden4 ,now let us unpin our ,beetle1 turn it on its back1 and examine it from the under side4 ,head1 thorax1 and abdomen may be made out more clearly than before1 and we can see that the last two regions are divided into segments4 ,let us deal with the head first4 ,this may be easily separated from the thorax with a dissecting needle1 or with a pocket-knife--an exceedingly handy tool4 ,the huge goggle-eyes cannot escape observation2 and1 even without a magnifier1 they may be seen to be compound--that is1 made up of a number of facets1 which show like a fine network4 ,just in front of the eyes are the antennae1 which serve as organs of touch and perhaps also of other senses4 ,kirby has recorded facts which seem to show that the antennae 7in some cases7 are also organs of hearing4 ,other authorities1 after many observations1 have come to the same conclusion4 ,the matter1 however1 is beset with difficulty4 ,it is certain that some ,insects have their ears in their legs2 and for the present1 at any rate1 we may be satisfied to know that the antennae are sense-organs1 certainly of touch1 probably of smell1 and1 in some cases1 of hearing4 ,an excellent authority on the subject is ,sir ,john ,lubbock's book1 ,the ,senses of ,animals#aa1 which contains references to very many original papers4 ,illustration3 ,,fig4 #ba4 ,,fig4 #ba4--,upper surface of head of ,dytiscus4 a1 labrum1 or upper lip2 b1 clypeus or shield2 c1 mandible dissected out1 and 7d7 reversed2 e1 eye2 f1 antennae4 ,illustration3 ,,fig4 #ba ,a4 ,,fig4 #ba ,a4--,under surface4 a1 mentum or chin2 b1 ligula or tongue2 c1 labial palp2 these three together forming the labium1 or lower lip2 e1 eye2 f1 antennae4 ,above the maxillae1 or lower jaws 7d d71 are shown dissected out3 d#a1 inner or palpiform lobe2 d#b1 maxillary palp2 d#c1 lacinia or blade2 d#d1 the palpifer or piece that bears the palp 7d#b72 d#e1 stipes or stalk2 d#f1 the cardo or hinge4 ,now we may pass to the mouth parts4 ,it will be good practice to dissect these out1 either in air or in water4 ,we may hold a ,beetle between the finger and thumb of the left hand1 and separate all the parts with a needle held in the right4 ,it is a good plan to gum these parts on a card1 for comparison with the figures in our favourite book--whatever that may be--on ,natural ,history1 and also with the mouth parts of insects of other ,orders4 ,for however much these may differ in form1 and in the uses to which they are put1 they are really modifications of the same parts4 ,in ,fig4 #ba we have the upper side and in ,fig4 #ba;,a the under side of the head represented1 so that we may easily get acquainted with the different parts1 and the names given to them4 ,the cut should be gone over several times1 and the parts in the picture compared with those in the specimen under consideration4 ,it is good practice to endeavour to draw what is seen from the specimen itself1 and then to compare the result with the work of the trained artist4 ,and the mouth parts of ,dytiscus may be compared with the mouth parts of the ,cockroach 7,fig4 #cc74 ,illustration3 ,,fig4 #bb4--;,disposition of mouth parts4 ,returning to practical work1 the first thing is to separate the labrum1 or upper lip1 from the head4 ,then the large mandibles should be dissected out1 and cleaned 7by soaking in caustic potash7 from the muscles which will come away with them4 ,behind these are a smaller pair of jaws1 the maxillae1 furnished with a pair of palps1 called maxillary palps from their position4 ,these are to be dissected out2 and then the lower lip1 or labium1 may be separated by passing a sharpened needle along the line where it joins the chin4 ,the palps on the lower lip are called labial palps4 ,when these parts are cleaned and dried1 they should be gummed on card1 as shown in ,fig4 #bb1 where the long lines represent the upper and lower lips respectively1 and the shorter ones the mandible and maxilla of each side4 ,so much for the head4 ,now we discover that what appeared to be the thorax1 when we were looking at the upper surface of the ,beetle1 and what is called the thorax in descriptions of ,beetles1 is really but a portion of that region1 which is seen to be divided into segments4 ,the covering on the upper surface protects only the first segment1 the middle and hinder ones being covered by the wing-cases and the scutellum 7a triangular piece jutting backward from the second segment1 and meeting the suture74 ,this is not represented in ,fig4 #ag2 but we may put in with our pen a tiny triangle1 with its base towards the head1 and its apex towards the tail--this will meet the case4 ,the first segment bears no appendage above1 but to the under side is attached the first pair of legs4 ,the middle segment also carries a pair of legs1 and on its upper surface are the wing-cases1 to the under side of which1 and to the body1 the winglets are joined4 ,the last segment bears the wings above1 and the last pair of legs below1 these being placed very far back1 so as to give them greater power in propelling the animal through the water4 ,it will be convenient to examine the legs next4 ,first1 however1 it will be well to look at a normal leg of an ,insect 7the ,cockroach71 and learn the names of the different parts4 ,first comes the coxa 7a7 or haunch1 next the trochanter 7b71 then the femur 7c7 or thigh1 the tibia 7d7 or shank1 and the tarsus 7e7 or foot1 ending in a pair of claws4 ,there are three pairs of legs in perfect ,insects1 and usually the same number in larval forms1 though in some of these legs are entirely wanting4 ,illustration3 ,,fig4 #bc4--,leg of ,cockroach4 ,in the males of the ,margined ,water ,beetle and many of its near relations the first pair of legs deserve special attention4 ,the first three joints of the tarsus have coalesced to form a disk or cup1 which in our specimen bears two smaller ones on its inner surface4 ,a power of #bj will show the disk nearly as well as it appears in ,fig4 #bd4 ,the purpose of this disk1 or clasper1 which is absent in females1 is obvious4 ,it was formerly supposed to act as a sucker1 but ,professor ,lowne and ,professor ,miall#ab have shown that it does not act by atmospheric pressure1 but by a viscid secretion discharged from the cup-like hairs with which the inner surface is set4 ,illustration3 ,,fig4 #bd4--,tarsus of ,dytiscus 7magnified74 ,the middle pair of legs in the male also bear cup-like hairs on the corresponding joints of the tarsus1 and in very much greater number4 ,professor ,miall quotes ,simmermacher to the effect that while the large disk on the fore-leg has #agj sucking-hairs1 the enlarged joints of the tarsus of the middle leg bear no less than #aeij4 ,these hairs are plainly discernible with the half-inch ,steinheil1 and ,i have made them out with the inch1 and think that ,i could show them to anybody else with that power4 ,i have not looked for these sucking-hairs on the middle leg of other ,beetles of the same family which have disks on their fore-legs1 but they do exist in some other genera4 ,if we watch a male ,dytiscus in life1 in a small aquarium1 we shall soon be convinced that ,lowne and ,miall are correct in their statement that the cup-hairs discharge an adhesive substance4 ,we shall see this all the more plainly if there is much floating vegetation4 ,for1 in swimming about1 the ,beetle will often come in contact with some of this1 and it will adhere to the cup-hairs4 ,his struggles to free himself from the encumbrance will show that the attachment is not altogether under his control4 ,the offending weed is rubbed against the spines of one of the other legs till it is removed4 ,illustration3 ,,fig4 #be4--;,female ,dytiscus swimming4 ,the spines with which the legs are set are worthy of a good deal of attention1 and1 like the adhesive cup-like hairs1 though in different fashion1 they doubtless assist the animal in holding its prey4 ,the first and middle legs end in strong claws2 those of the last pair are not so well developed4 ,the last pair of legs are the swimming organs4 ,the tibia and tarsus are fringed with long stiff hair behind1 so as to hold the water when the ,beetle swims4 ,a peculiar arrangement of the first joint of the tarsus allows the edge to be presented to the water when the limb is carried forward for the return stroke1 thus offering the least possible resistance4 ,this ,dr4 ,sharp has compared to the action of a rower in feathering his oar4 ,there is1 however1 this difference1 which it is well to note4 ,the oar is feathered after the stroke2 the ,beetle feathers its legs before the stroke4 ,it is the first motion when it begins to swim1 and the action is not peculiar to the male4 ,we now come to the third region1 the abdomen4 ,like the thorax it is visibly divided into segments1 though the division between them is not so great4 ,much difference of opinion exists as to the number of segments in the abdomen of a typical insect4 ,some authorities maintain there are eleven1 while others put the number as low as five4 ,this1 however1 is theoretical rather than practical4 ,it is enough for us to know that the number apparently varies greatly1 owing to the coalescence of two or more of the segments4 ,illustration3 ,,fig4 #bf4--,upper surface of abdomen of typical ,beetle4 ,the head in ,insects1 we have seen1 carries the eyes1 antennae1 and feeding organs4 ,the thorax bears the legs and wings4 ,the abdomen bears no appendages1 except in some cases1 on the last segment2 these are called cerci4 ,it may be1 however1 that the stings of bees and the ovipositors of saw-flies and other insects are modified appendages4 ,on examining the abdomen of ,dytiscus we shall probably be struck with the difference in appearance between the upper and the under surfaces4 ,the latter is hard1 smooth1 and shiny2 the former1 when the wings are removed1 is seen to be covered with felt-like hair4 ,our interest is with the upper surface4 ,along the abdomen on each side lie spiracles1 stigmata1 or openings to the breathing tubes4 ,the first and last are larger than the rest1 and their general form can be readily made out with an inch magnifier1 and with the half-inch we may get some idea of the detail shown in ,fig4 #bg4 ,illustration3 ,,fig4 #bg4--,spiracle of ,dytiscus 7magnified74 ,dytiscus breathes in this way4 ,floating up to the top of the water1 the end of the abdomen projects above the surface4 ,if one watches the ,beetle the wing-cases will be seen to rise a little4 ,the air retained by the felted hairs is given off1 and a further supply taken in4 ,then the wing-cases are lowered again2 the ,beetle gives two or three strokes with its swimming legs1 and descends below the surface to ramble round the tank in search of food4 ,illustration3 ,,fig4 #bh4--,tracheal tubes 7magnified74 ,this air-supply between the wing-cases and the abdomen is taken in at the spiracles and distributed through the tracheal tubes throughout the body4 ,these tubes branch and subdivide till they end in small twig-like vessels comparable to the capillaries of the human body4 ,they consist of two layers--the inner strengthened by what probably is a spiral fibre1 though ,packard believes that1 in some cases at least1 it consists of similar rings4 ,but we must not pursue this subject4 ,it would lead us beyond our appointed limits4 99 99 99 99 99 ,another ,beetle fairly common in stagnant waters round ,london and in the southern counties is that to which the name ,great ,water ,beetle 7,hydrophilus piceus7 of right belongs4 ,this name is sometimes wrongly applied to ,dytiscus1 with which its rightful owner has little in common1 except its aquatic habitat4 ,its scientific name is ,hydrophilus piceus2 but we shall speak of it as ,hydrophilus4 ,it is not a very easy matter to take this ,beetle with a net1 by sweeping in the ordinary way1 for it likes to get into the middle of a mass of vegetation1 where it is sure of a good food supply1 and is probably safe from the attacks of ,dytiscus1 who not unfrequently makes a meal of his larger relation4 ,a good plan is to pass the net under a mass of weed and then shake it to and fro in the water4 ,by this means any ,beetles in the weed will be dislodged from their hiding-places1 and fall down into the bottle4 ,they have1 in confinement1 the same habit of making a snug place for themselves2 and more than once ,i have fancied that a ,beetle of this species had escaped from the aquarium1 when all the time it was hidden in a thick patch of water-moss4 ,they are practically vegetable feeders1 though ,dallas says that they are not such strict vegetarians as to deny themselves a meal of animal food when they meet with a dead mollusc or larva in the course of their wanderings4 ,i have never known them to indulge in animal food1 dead or living1 but ,i have known them refuse it4 ,hydrophilus is the largest ,british ,water ,beetle1 and1 with the sole exception of the ,stag-,beetle1 the largest ,british member of the ,order4 ,its total length is very little less than two inches1 and across the middle of the back it measures about half as much4 ,it is more slenderly built than ,dytiscus1 and the contrast in the size and armature of the legs is very striking 7,fig4 #bi74 ,there is also a great difference in their method of progression through the water4 ,dytiscus moves both legs simultaneously1 while ,hydrophilus walks rather than swims1 moving one leg after the other4 ,if we cannot collect this ,beetle for ourselves--which we should endeavour to do1 if possible--it may be bought of almost any dealer in what are called #8aquarium requisites4' ,but prices rule higher for ,hydrophilus than for ,dytiscus4 ,bateman says that this species is rarer than formerly1 and that specimens cost from #as4 to #bs4 #f;d4 a pair1 #8according to the dealer and the season4' ,from this ,i gather that ,i must have gone to a shop where the prices were reasonable1 for ,i have never paid more than #f;d4 for a ,hydrophilus1 and then have been allowed to pick out a male4 ,at the same shop ,i have paid #b;d4 for ,dytiscus4 ,illustration3 ,,fig4 #bi4--;,great ,water ,beetle4 a1 male2 b1 female2 c1 larva2 d1 pupa4 ,in keeping this ,beetle we shall need a larger vessel than was required for ,dytiscus4 7,in both cases the aquarium should be covered1 for if food be scarce1 and sometimes for other reasons1 both these ,beetles may take to flight47 ,the aquarium should be well supplied with growing water-weed1 but none that is choice or valuable should be put in1 for in moving about over the weed the animal will damage almost if not quite as much as it eats4 ,this difficulty can be easily got over by supplying it with anacharis1 water-crowfoot1 milfoil1 or any other common plant that grows rapidly and is easily procurable4 ,the only specimen that ,i have taken myself was captured a few miles north of ,london4 ,it exhibited a strange instance of depraved appetite4 ,in the large tank into which it was put were growing vallisneria1 frog-bit1 and water-crowfoot in plenty4 ,these it was never seen to touch4 ,the tank1 at one time1 had been used for newts1 and floating on the surface was a piece of virgin cork4 ,it had served the former inmates as a kind of island continent1 and had never been removed4 ,to the under side of this the ,beetle would moor himself1 head downwards1 and nibble away1 as if cork were the natural diet of a ,british ,water ,beetle4 ,in a few days the ,beetle died4 ,it was put into spirit1 and soon after became the subject of a post-mortem4 ,but its strange diet was not the cause of its death1 which was sufficiently accounted for by injuries inflicted before its capture1 probably by a larval or an adult ,dytiscus4 ,it would be mere waste of time to go over this ,beetle and describe it point by point1 as was done with ,dytiscus4 ,if what was there written was of any value1 readers will be able to apply for themselves the method laid down4 ,there are1 however1 some points of difference to which it will be well to invite attention4 ,it is a good plan to lay specimens of these ,beetles side by side for comparison4 ,hydrophilus is the larger of the two2 and differs in colour as well as in size4 ,its hue is black with an olive tinge2 and in certain lights a blue-black metallic gloss may be seen on the outer margins of the wing-cases4 ,these are marked with faint longitudinal lines1 and each bears three rows of dots running in the same direction4 ,the greater length and more slender build of the legs of ,hydrophilus are at once apparent4 ,there is also a marked difference in the tarsal joints of the fore-legs of the male4 ,the disks and cup-like hairs of ,dytiscus are absent in ,hydrophilus1 but in their stead the last joint bears a sub-triangular plate1 studded on the inner surface with spines1 which probably serve a similar purpose4 ,a great deal of valuable information about organs of this kind and their functions will be found in chapter ,x of ,darwin's ,descent of ,man4 ,simmermacher's paper#ac should be consulted by all who have the opportunity4 ,our inch magnifier will show us these spines quite clearly2 and also a curious little bunch of bristles1 which ,simmermacher says are probably organs of touch4 ,it is a good plan to take ,hydrophilus out of the water1 and lay it upon its back1 so that the difference between it and ,dytiscus may be clearly seen4 ,the ,beetle should be handled carefully1 for on the thorax is a kind of keel1 ending in a sharp spine1 which extends over part of the abdomen4 ,this spine is free1 and may easily wound the hands of those who do not watch the motions of the creature pretty carefully4 ,the fore part of the abdomen and the thorax are covered with short close hairs1 and when the ,beetle is in the water these parts entangle a layer of air1 which gives it the appearance of being covered with quicksilver4 ,the two ,beetles differ also in their method of exchanging impure for pure air4 ,dytiscus1 as we have seen1 takes in a fresh supply under its wing-covers behind2 ,hydrophilus takes in a fresh supply in front1 employing for this purpose the antennae1 which apparently do not function as feelers1 as is generally the case4 ,when ,hydrophilus wants to take in a supply of pure air1 it rises to the top of the water1 slowly and deliberately4 ,unlike ,dytiscus1 it is never in a hurry4 ,then one of the antennae is pushed through the surface film1 thus communicating with the air1 which descends to the hair-covered thorax1 whence it reaches the spiracles on the upper surface of the abdomen4 ,to allow of this the wing-cases are slightly raised in front4 ,the spiracles in ,dytiscus are larger at the posterior end of the abdomen3 in ,hydrophilus the largest spiracles are in front4 ,this is what might be expected1 from the method adopted in each case for procuring a fresh supply of air4 ,these ,beetles have frequently bred in confinement2 but no better account than that of ,lyonnet has ever been given of the operation of the female in making her cocoon and depositing her eggs4 ,as his account is not generally available1 a condensed translation of it is inserted with his illustration4 ,illustration3 ,,fig4 #cj4--;,female ,hydrophilus constructing a cocoon4 7,after ,lyonnet47 ,lyonnet#ad wanted to find out how the female made the cocoons 7,fig4 #cj71 and this is how he set to work4 ,he put some of these ,beetles into a large aquarium1 with a good quantity of water and some duckweed4 ,on ,may #ca and the following day he noticed that one of the females was swimming about in every direction1 as if in search of something4 ,thinking that this was because she had not the proper materials for her work1 he then put into the aquarium some thread-like alga of a kind which he had seen attached to some cocoons1 and on ,june #c the ,beetle began to make a cocoon1 but soon gave up the task1 apparently because she was troubled by other aquatic insects which had made a home in this weed4 ,these intruders were removed1 and the ,beetle set to work once more4 ,lyonnet then noticed that1 like a spider1 she had her spinning apparatus at the posterior end of the body4 ,she extended the last segments slightly1 and opened the hindmost one1 when he saw a nearly circular opening1 in which was a whitish disk 7,fig4 #cj;,a1 a74 ,on this disk were two little brown tubercles side by side1 nearly at right angles to the longitudinal axis of the body4 ,from each there projected a blackish-brown conical tube1 about a line long1 stiff towards the base1 but flexible and elastic towards the tip4 ,these tubes were the spinnerets1 which acted together with a parallel movement1 and from each proceeded a separate thread4 ,and this is how she made her cocoon4 ,she lay near the surface of the water back downwards1 the under part of the body and the second and third pair of legs buried in the thread-like weed4 ,the front legs were free1 and with these she shaped the weed over her abdomen4 ,then she spun a covering of white silk against the under side of the weed4 ,while she was spinning1 from time to time she used her front legs to press and flatten the work against her body 7,fig4 #cj;,b71 giving it the shape of a flattened arch1 to which her body gave the requisite curve4 ,this1 forming the top of the cocoon1 was finished in about half an hour4 ,then she turned 7,fig4 #cj;,c71 and spun the bottom of the cocoon1 moulding this1 like the top1 on the curve of her abdomen1 and uniting the top and bottom with silk which she spun4 ,the work occupied about an hour and a quarter4 ,the ,beetle then remained nearly in that position for some two hours4 ,at first she was hidden in the cocoon quite up to the thorax4 ,the body1 however1 was withdrawn almost imperceptibly4 ,during this time she was busy laying her eggs in regular order1 with the pointed ends upwards4 ,after this she came out of the cocoon1 and closed the mouth 7,fig4 #cj;,d71 making the opening smaller by degrees4 ,then she made a little mast 7,fig4 #cj;,d1 b71 of the use of which ,lyonnet admits his ignorance1 suggesting1 however1 that its construction may serve to use up the silky matter remaining after the work is finished1 lest it should acquire harmful qualities in the body of the ,beetle4 ,the true explanation seems to be that it serves to convey air to the eggs inside the cocoon4 ,on ,july #ag ,lyonnet was rewarded for his patient watching by seeing a larva come out of the cocoon1 and the next day some fifty more appeared4 ,what he saw and recorded it is in the power of others to see1 if they will imitate his patient observation4 ,the ,cocktail ,beetle1 or ,devil's ,coach ,horse 7,ocypus olens71 is an excellent specimen of a ,land ,beetle to examine1 for it is of fairly large size and extremely common4 ,moreover it does well in captivity1 so that there will be no difficulty in watching its habits in life1 and pickling it for closer examination when dead4 ,during the day these animals usually lie concealed under stones or pieces of earth1 coming forth at dusk and during the night in search of food4 ,occasionally1 however1 they may be met with in daylight1 leisurely stalking a smaller beetle or a fly2 then with a dash seizing the victim in their powerful mandibles1 which are quite capable of making an impression on the human skin1 as those who handle these ,beetles unwarily will discover for themselves4 ,illustration3 ,,fig4 #ca4--;,cocktail ,beetle4 a1 larva2 b1 pupa4 ,nothing of an animal nature comes amiss to them1 and if they cannot capture living prey1 they will make a hearty meal off carrion4 ,this is an advantage to us1 for we may feed our captives with dead insects or with small pieces of meat4 ,this ,beetle is about an inch long1 and of a deep dull black colour4 ,the head is joined to the thorax by a distinct neck1 and the abdomen is naked1 owing to the fact that the wing-cases are very short4 ,its wing-cases bear about the same proportion to those of the ,margined ,water ,beetle that a man's frock-coat bears to a boy's ,eton jacket4 ,and this ,beetle may be taken as a good type of a group--the ,beetles with short wing-cases 7,brachelytra74 ,the attitude of this animal when irritated or alarmed is well depicted in ,fig4 #ca4 ,it raises its head menacingly and opens its strong mandibles to their full extent1 at the same time turning up the end of the abdomen1 like a scorpion about to sting4 ,from the last segment it will often put forth a pair of white vesicles1 from which is discharged a volatile liquid of disagreeable odour1 that probably acts as a defence against insect-eating creatures4 ,the best way to capture one of these ,beetles is to pick it up with what ,kirby calls the #8natural forceps'--the finger and thumb4 ,it may be dropped into any convenient receptacle2 the small metal boxes in which vestas are sold will answer the purpose very well4 ,my specimen was given me by a friend1 who kept it with another in a round tin box4 ,it lived with me for about three months in a four-ounce bottle1 that measured three inches in height1 to the neck1 and two inches in diameter4 ,the bottom was covered to the depth of about an inch with garden soil1 and the top tightly corked1 to prevent the prisoner's escape4 ,this precaution was necessary2 for the inside of the bottle1 though cleaned from time to time1 soon became covered with a coating of earthy particles1 which afforded the ,beetle a pretty firm foothold4 ,it was an extremely interesting pet1 and its struggles to escape by climbing up the sides of the bottle often afforded me much entertainment4 ,it seemed to have a glimmering notion that the only way out was by the top1 and knowing nothing of the cork it would rear itself up against the side1 and try to climb up by vigorous movements of its fore-legs4 ,it would also take advantage of any little lump of earth projecting about the rest4 ,it had not intelligence enough to make anything like a mound for itself1 though the inequalities were probably the result of its burrowing under the surface4 ,its temper was none of the best1 for if it was disturbed with the forceps it would resent it fiercely4 ,the mandibles would be opened1 the abdomen curled up1 and out would come the two vesicles as a means of defence4 ,if the forceps were put near the mandibles1 they would be seized1 and the ,beetle would hold on so tenaciously that it has often been lifted out of its bottle in this fashion4 ,it was exceedingly voracious1 and was generally fed on garden worms4 ,after a full meal its increase in size was very evident4 ,this is not to be taken to mean that insects grow after they have attained the perfect or imago state1 for this is not the case4 ,but when they have had a long fast1 the segments approach each other1 and are forced apart when the creature is gorged with food4 ,if a ,beetle of this species were kept fasting for some days1 and then carefully measured1 and measured again after being plentifully supplied with worms or flies1 there would be a difference of some millimetres between the results4 ,dallas has an interesting passage in his ,elements of ,entomology respecting the boldness of the larval form1 which is worth quoting4 #8,i have seen one engaged in a struggle1 which lasted about twenty minutes1 with a worm of some five inches in length1 the larva being scarcely more than an inch long4 ,during this contest the little savage crept under the worm1 fixing his mandibles into the creature's body in various places1 each bite apparently producing a considerable swelling4 ,sometimes he would fasten upon the head of the worm1 and retain his hold with the pertinacity of a thoroughbred bulldog1 although twisted about in every direction by the struggles of his intended victim4 ,at last1 however1 he seemed to come to the conclusion that he had been too ambitious in his desires1 and went quietly off amongst the grass1 rather prematurely1 as it seemed to me1 for when the worm began slowly to leave the field of battle1 about an inch of his tail was attached to the rest of his body solely by the intestine1 a union which the jaws of the larva would easily have dissolved4' ,i have never seen a fight between a larva and a worm1 for the few larva ,i have kept have been fed on flies4 ,but the adult ,beetle which has once fastened on a worm cannot be shaken off4 ,it will grip its prey with the first pair of legs1 fixing the claws in the skin1 and will finish a worm three inches long at a meal4 ,a dead specimen should be looked over in the way recommended for ,dytiscus1 raising the small wing-covers and unfolding the wings4 ,the spiracles are to be looked for at the sides of the abdomen1 in the groove formed by the meeting of the upper and under plates of each segment4 ,the short downy hair with which the body is covered should be noticed1 and the front legs are well worth examination4 ,the tibia or shank is armed with a strong spine1 and between this part of the leg and that which follows it is a notch1 through which the ,beetle passes its antennae to clean them from dirt4 ,the peculiar shape of the joints of the tarsus or foot is very plainly discernible with the appliances at our command1 and by a careful management we may make out the different kinds of hairs with which four out of the five of these joints are furnished2 some stout and spine-like1 others finer1 ending in a pear-shaped bulb4 ,these last probably serve the same purpose as the sucking-disks of ,dytiscus and the tarsal plates of ,hydrophilus4 ,,chapter ,,iii ,,cockroaches2 ,,earwigs2 ,,the ,,great ,,green ,,grasshopper2 ,,the ,,water ,,scorpion2 ,,the ,,water ,,boatman2 ,,corixa4 ,the next insect to come within range of our pocket lens is the ,common ,cockroach 7,blatta orientalis#ae71 popularly misnamed the ,black ,beetle4 ,we shall have no difficulty in procuring material for examination4 ,housekeepers will tell us that these creatures are only too plentiful4 ,in the last chapter we dealt with ,sheath-winged ,insects--the ,coleoptera4 ,cockroaches belong to the ,orthoptera1 or ,insects with ,straight ,wings4 ,the mouth-parts resemble those of ,beetles4 ,the chief differences that mark off the ,cockroaches and their kin from the ,beetles are the incomplete metamorphosis which the former undergo1 and the character of the wings4 ,straight-winged ,insects1 when they leave the egg1 differ little in shape from the adult1 except in the fact that they have no wings2 and these appendages are absent1 or so small as to be useless for flight in many species4 ,when wings are present the first pair are of little or no use for flight4 ,they are not1 however1 hard chitinous sheaths1 meeting in the middle line--that is1 straight down the centre of the back--but of a flexible leathery or membranous substance1 and they usually overlap each other at the tips4 ,the hinder wings are large and nearly semicircular4 ,the principal veins radiate from the centre to the circumference1 like the sticks of a fan1 and when the wings are folded up they lie straight along the upper surface of the abdomen4 ,it is from this fact that the ,order derives its name4 ,there are two great groups1 or sections1 of ,straight-winged ,insects--those that run1 like the ,cockroaches1 and those that leap1 like the ,grasshoppers4 ,no ,straight-winged ,insect is aquatic4 ,the ,common ,cockroach1 now so abundant1 is not a native1 but an importation from ,asia2 though how it reached this country is not quite certain1 probably by way of ,holland4 ,it seems to have established itself in ,london by the end of the sixteenth century1 and some two hundred years later we find ,gilbert ,white recording 7in or before #agij7 that #8a neighbour complained that her house was overrun with a kind of black beetle1 or1 as she expressed herself1 with a kind of black-bob1 when they got up in the morning before daybreak4 ,soon after this account ,i observed an unusual insect in one of my dark chimney closets1 and find since1 that in the night they swarm also in my kitchen4444 ,the male is winged1 the female is not1 but shows something like the rudiments of wings1 as if in the pupa state4444 ,they are altogether night insects1 lucifugae1 never coming forth till the rooms are dark and still1 and escaping away nimbly at the approach of a candle4' ,this description leaves no doubt as to what the #8black-bobs' really were4 ,this name seems to have dropped out of use1 and it would be well if #8black beetle1' in the sense of ,cockroach1 were also allowed to drop1 for the term contains just as many errors as words4 ,we may make our first acquaintance with these insects by keeping some specimens in confinement4 ,a tin box1 with a glass lid1 will make a capital dwelling for them4 ,some paper should be put in1 for them to hide in away from the light1 and there can be no difficulty in providing them with food4 #8,bark1 leaves1 the pith of living cycads1 paper1 woollen clothes1 sugar1 cheese1 bread1 blacking1 oil1 lemons1 ink1 flesh1 fish1 leather1 the dead bodies of other cockroaches1 their own cast skins and empty egg-capsules1 all are greedily consumed4 ,cucumbers1 too1 they will eat1 though it disagrees with them horribly#af4' ,we have ,dr4 ,sharp's authority for the statement that in confinement these insects are rather amusing pets1 as they #8occasionally assume most comical attitudes1 especially when cleaning their limbs4 ,this they do somewhat after the fashion of cats1 extending the head as far as they can in the desired direction1 and then passing a leg or an antenna through the mouth2 or they comb other parts of the body with the spines on the legs1 sometimes twisting and distorting themselves considerably in order to reach some not very accessible part of the body#ag4' ,the prejudice against these insects is1 however1 so strong1 that most people will prefer to examine dead rather than living specimens1 on account of the disagreeable odour of the latter4 ,this odour is due to a fetid excretion from the mouth1 and if the specimens are killed by dropping them into boiling water1 this will be discharged1 and after a little while they may be taken out with a pair of forceps1 and put into spirit for preservation4 ,if they are dropped alive into spirit1 the excretion will communicate its strong scent to the preserving medium1 and this should be changed before the insects are examined4 ,from ,fig4 #cb we may get a general idea of the appearance presented by a male or female1 lying back upwards in a small glass dish1 ready for examination with the pocket lens4 ,the female may be distinguished at a glance by her wingless condition--only rudiments of wing-cases being present1 and no wings--and her broader abdomen4 ,in life she does not stand so high upon her legs as does the male1 and her abdomen trails along the ground4 ,the male does not acquire his wings till the last moult4 ,illustration3 ,female4 ,male4 ,,fig4 #cb4--;,cockroaches4 ,as the ,cockroach lies back uppermost in a glass dish1 the head is almost concealed4 ,this is especially the case1 unless the insect is flattened out in some way1 or pinned down to a piece of weighted cork4 ,there will thus be1 apparently1 two1 instead of three main divisions4 ,this arises partly from the fact that the head is deflexed1 or bent down so that the mouth is turned towards the rear1 and partly because the first segment of the thorax bears a chitinous shield1 roughly semicircular1 which covers so much of the head as would otherwise be visible4 ,the difficulty1 however1 may be easily got over1 by reversing the position of the insect1 and raising the head with a needle4 ,the antennae will attract attention by their great length4 ,in the male insect they exceed1 while in the female they fall a little short of1 the total length of the body4 ,they are well worth examination4 ,even a low power will show that they consist of a number of joints--usually from seventy-five to ninety4 ,the three basal joints are much larger than the rest1 and in the female the third basal is nearly as long as the first4 ,all these joints are thickly set with stiff hairs directed forwards4 ,at the outer side of each antenna is a compound eye1 and on the inner side is a pale spot1 the fenestra1 which in the males of some foreign ,cockroaches is replaced by a simple eye4 ,if ,cockroaches are kept in confinement1 and forced out into the light1 the constant motion of the antennae will satisfy the observer that they are of great use to their owners4 ,by means of these organs they not only discover their food1 but become by some means1 probably by the motion of air-waves1 aware of danger that threatens them4 ,belt1 in his ,naturalist in ,nicaragua 7p4 #aaj71 speaking of the ,cockroaches that infest houses in the tropics1 says1 #8,they are very wary1 as they have numerous enemies--birds1 rats1 scorpions1 and spiders2 their long1 trembling antennae are ever stretched out1 vibrating as if feeling the very texture of the air around them2 and their long legs quickly take them out of danger4' ,it is not given to every one to visit the tropics1 but we may all use our eyes in observing the common insects that abound in our country1 and in doing this we shall strengthen the habit of observation1 and very often find confirmation of what we read of the habits of insects in distant lands4 ,sir ,john ,lubbock#ah1 in treating of the sense of smell in ,insects1 says that #8,plateau put some food of which cockroaches are fond on a table1 and surrounded it with a low circular wall of cardboard4 ,he then put some cockroaches on the table3 they evidently scented the food1 and made straight for it4 ,he then removed their antennae1 after which1 as long as they could not see the food1 they failed to find it1 even though they wandered about quite close to it4' ,the large kidney-shaped compound eyes are sure to attract attention4 ,it is worth while to take out and break up an eye1 gently washing out the pigment4 ,if we do this1 and then examine it with the pocket lens1 we shall have some idea of the multiplicity of lenses in the eye of a ,cockroach1 each of the six-sided facets being a lens4 ,next come the mouth parts1 which may be run over very quickly1 for those of ,beetles are formed upon the same plan1 and from this primitive plan are derived the mouth parts of all other ,insects1 of whatever character they may be4 ,to examine the mouth organs the insect must be turned on its back1 and the labrum 7a71 or upper lip1 raised with a needle1 so as to allow of a general view of the rest4 ,then the jaws or mandibles 7b7 may be picked out with a needle4 ,these jaws are strongly toothed1 and work from side to side1 and it is easy to see that they are very efficient organs4 ,the lower jaws 7c71 or maxillae1 lie below1 and are compound organs1 each being made up of several parts--the base1 called the cardo or hinge 7not shown in the illustration1 but connected at right angles by a joint with the lower part1 the stipes74 ,from the stipes rise the galea1 or helmet1 on the outer side2 and1 on the inner side1 the lacinia1 to which the name maxilla is often applied1 though it properly belongs to the whole4 ,at the base of the galea is inserted the five-jointed maxillary palp1 thickly set with hairs1 and probably an organ of touch4 ,illustration3 ,,fig4 #cc4--,mouth parts of a ,cockroach4 ,by examining the maxillae 7c7 before they are separated1 and comparing them with the labium 7c7 or under lip1 which closes the mouth from below1 it will be evident that there is no slight similarity between them4 ,nor is this strange3 for the under lip consists of the second maxillae joined at their bases1 which form the submentum 7s7 and mentum 7m74 7,the former is the small1 the latter the large white basal portion2 the vertical line in the illustration shows the mental suture1 and should be traced in the dead insect47 ,the organs in the centre constitute the ligula2 and on each side of the labium is a three-jointed palp 7labial71 like that on the maxillae1 thickly set with hairs1 and with a similar function4 ,it is well to work over the mouth parts a few times till the relation between the maxillae and the labium is seen and understood4 ,the internal tongue 7d7 is attached to the inner side of the labium4 ,now1 still working on the under side of the insect1 the three segments of the thorax are to be made out1 and one cannot fail to notice the great size of the first joint 7the coxa7 in all the legs1 and that these joints seem to serve as shields to protect the under side of the thorax4 ,then the different parts of the legs should be traced1 and compared with ,fig4 #bc on p4 #dd4 ,the spiny armature of the tibiae is to be noticed1 as are the claws1 between which is a projecting lobe1 though this is absent in immature specimens4 ,we shall find that the appendages of the thorax are the same as in the ,margined ,water ,beetle4 ,it is well to take as little as possible on trust1 and to verify everything that we possibly can4 ,now we may reverse the position of our subject1 and having cut off the wing-cases1 which are technically called tegmina1 examine the wings4 ,these may be gently unfolded with a needle or a camel's hair brush1 when the longitudinal method of folding will be clearly seen1 and the difference of the veining from that of the wings of the ,margined ,water ,beetle will be apparent4 ,a female should also be examined1 and the small tegmina cut off1 so as to see that not even the rudiments of wings are present4 ,the ,cockroach breathes like other adult ,insects1 and the spiracles are ten in number--two on the thorax and eight on the abdomen4 ,the thoracic spiracles may be pretty readily seen1 but those on the abdomen are not so easy to make out4 ,but by cutting away1 with a fine pair of scissors1 the edges of the plates that cover the upper and under surfaces of the abdomen and the membrane that unites them 7,fig4 #cd71 we may discover them as the open ends of small tubes4 ,while dealing with the insect in this fashion1 it will be easy to take out a piece of the tracheal tube1 which may be compared with ,fig4 #bh4 ,illustration3 ,,fig4 #cd4--;,cockroach1 showing ,spiracles4 ,the abdomen consists of a series of rings or segments1 the exact number of which is rather difficult to decide1 from the fact that some are concealed and others altered in form4 ,dr4 ,sharp#ai says that #8it is considered that ten dorsal and ten ventral plates exist1 though the latter are not so easily demonstrated as the former4' ,in the male1 ten above 7dorsal7 and nine below 7ventral71 and in the female two less in each case1 may be made out without dissection4 ,from the sides of the tenth segment two organs1 the cerci 7,fig4 #ce1 a71 are given off1 one on each side4 ,these may be distinguished from the styles of the males by their presence in both sexes4 ,our inch lens will show that each cercus consists of sixteen rings4 ,if we use the half-inch1 we shall see that each ring is set with hairs of different lengths4 ,when we have got so far it may be well to compare the structure of a cercus with that of an antenna 7p4 #fg74 ,in each we have a succession of jointed rings giving flexibility to the organ1 and the rings in each case are studded with hairs4 ,it has been shown pretty conclusively--and we may verify the experiments--that the antennae are sense-organs4 ,are we not justified in coming to the conclusion that1 since the antennae and the cerci resemble each other in structure1 they also resemble each other in function8 ,if the ,cockroach receives sensations by means of the antennae1 is it not probable that it also receives sensations by means of the cerci8 ,having worked over the ,cockroach from the outside1 it will be advantageous to get some acquaintance with its internal anatomy4 ,this is not a difficult matter4 ,the specimen is to be pinned down1 under water1 with its back uppermost4 ,the wings having been removed1 a longitudinal cut is to be made down the centre from the posterior part of the abdomen to the back of the head1 and the two sides of the integument turned back4 ,or the junction between the upper and lower plates on each side may be cut through with a cutting needle1 and the whole integument removed4 ,the first task is to clear away the fat-body1 a whitish substance which overlies the chief organs of the body4 ,when this is picked to pieces and floated off the digestive system will be exposed4 ,after this has been worked over a few times there should be no difficulty in dealing with similar parts in other ,insects4 ,at the back of the head lies the gullet or oesophagus leading into the crop 7c71 at the base of which lies the gizzard 7g74 ,the interior of this organ is furnished with six strong chitinous teeth1 with small ridges of the same substance between them4 ,towards the posterior end are six cushions1 all set with fine bristles4 ,behind this comes the stomach 7v71 into which open seven or eight tubes1 closed at one end1 and between it are the ,malpighian tubes1 which are concerned in the process of excretion4 ,the small intestine 7co7 succeeds1 and behind this is the rectum 7r74 ,illustration3 ,,fig4 #ce4--;,alimentary ,canal of ,cockroach4 ,it will be interesting to separate the gizzard from the crop 7c7 and stomach 7v7 and break it open with a couple of needles1 so as to examine the teeth1 which will be more easily made out if the opened organ be allowed to soak for a time in a solution of caustic potash4 ,similar teeth-like processes are found in the gizzards of many other ,insects1 and their presence has given rise to some strange ideas4 ,swammerdam#bj says1 #8,i preserve also the threefold stomach of a locust1 which is very like the stomach of animals that chew the cud1 and particularly has that part of the stomach called ,echinus#ba very distinctly visible4 ,i do not1 therefore1 doubt but locusts chew the cud1 as well as the animals just mentioned4 ,indeed1 ,i persuade myself that ,i have seen this4' ,somewhat similar teeth-like processes exist in the ,lobster1 the ,crab1 and the ,crayfish4 #8,professor ,plateau has expressed a strong opinion that neither in the stomach of ,crustacea nor in the gizzard of ,insects have the so-called teeth any masticatory character4' ,he adopts ,swammerdam's comparison1 but considers them strainers1 not dividers of the food#bb4 ,we may be fortunate enough to meet with some specimens of the ,american ,cockroach 7,periplaneta americana1 ,fig4 #cf71 a much larger species1 which has established itself in some few places in this country4 ,at the ,zoological ,gardens1 ,regent's ,park1 it is abundant1 and has almost1 if not entirely1 driven out the common form4 ,mr4 ,bartlett believes that it was introduced in cases in which animals have been sent over from ,america4 ,both sexes are winged4 ,they not only possess organs of flight1 but use them4 ,if one visits the ,gardens1 there will be no difficulty in getting specimens2 and it is interesting to compare the points of agreement in and of difference between this animal and our common form4 ,illustration3 ,,fig4 #cf4--;,american ,cockroach 7male74 ,the ,earwig 7,forficula auricularia7 is common enough to furnish us with plenty of specimens on which we may employ our pocket lens4 ,any garden in the summer months will yield an ample supply4 ,earwigs1 like ,cockroaches1 are light-shunning insects1 and love to hide themselves in the corollas of flowers2 and it is probably from their habit of seeking to conceal themselves that they have acquired their bad reputation--by no means confined to our own country--of creeping into the ears of persons lying asleep1 and causing death by getting into the brain4 ,such an occurrence is beyond the bounds of possibility4 ,no insect of this size could pass the drum of the ear4 ,we may easily keep these insects and observe their movements1 if we put them into a wide-mouthed glass bottle and supply them with food4 ,they are extremely fond of the flowers of the dahlia2 but a dahlia would offer too many hiding-places1 so we will put into the bottle some nasturtium flowers1 or any others with a bell-shaped corolla4 ,if we get a colony in spring we may watch the care of the female for her eggs4 ,according to ,kirby and ,spence#bc1 #8she absolutely sits upon her eggs1 as if to hatch them--a fact which ,frisch appears first to have noticed--and guards them with the greatest care4 ,de ,geer 7,mmoires1 iii4 #edh7 having found an earwig thus occupied1 removed her into a box where was some earth1 and scattered the eggs in all directions4 ,she soon1 however1 collected them one by one1 with her jaws1 into a heap1 and assiduously sat upon them as before4 ,the young ones1 which resemble the parents1 except in wanting elytra and wings1 444 immediately upon being hatched creep like a brood of chickens under the belly of the mother1 who very quietly suffers them to push between her feet1 and will often1 as ,de ,geer found1 sit over them in this posture for some hours4' ,mr4 ,kirby adds3 #8,this remarkable fact ,i have myself witnessed1 having found an earwig under a stone which ,i accidentally turned over1 sitting upon a cluster of young ones1 just as this celebrated naturalist has described4' ,like the ,cockroaches1 ,earwigs undergo an incomplete metamorphosis4 ,when the young leave the egg they resemble their parents1 as may be seen from the immature forms represented in ,fig4 #cg4 ,the resemblance becomes greater at each successive moult4 ,illustration3 ,,fig4 #cg4--,larva and ,pupa of ,earwig4 ,in working over these insects1 the forceps1 or pincers1 at the end of the abdomen will attract attention4 ,they are found throughout the family1 but little is known of their function4 ,it is said that they are used to aid in folding the wings1 and tucking them under the wing-covers4 ,this can scarcely be their only function1 for they are found in species that have no wings4 ,probably they serve as organs of defence and1 to some slight extent1 of offence4 ,when the abdomen is curled up1 these forceps certainly give the insect a threatening appearance4 ,they cannot1 however1 do much harm4 ,these forceps differ in shape in the male 7,fig4 #ch7 and female1 the blades being almost close together in the latter4 ,in the males they differ considerably in size4 ,of #ehc mature males taken in one day in the ,farne ,islands1 and examined by ,messrs4 ,bateson and ,brindley1 the forceps varied in length from #be mm4 to #i mm4#bd ,these are called respectively #8low' males and #8high' males4 ,the latter are in all points larger than the former1 and have been described as a separate species1 #8but it was impossible to get reliable measurements of the total length1 owing to the fact that the abdominal segments telescope into each other' 7cf4 p4 #cj74 ,after examining the antennae and dissecting out the mouth organs1 the peculiar overlapping or imbrication of the plates of the abdomen should be looked for2 and on the membrane that connects them the spiracles may be detected4 ,the wings and the complex method of folding have led some systematists to rank the ,earwigs as an ,order1 while some others rank them as a ,sub-order4 ,for the present1 at any rate1 we need not concern ourselves about this4 ,it is enough for us to know that they are closely related to the ,orthoptera4 ,as we look at the ,earwig from above1 the wing-cases recall to our mind those of the ,devil's ,coach ,horse 7,fig4 #ca71 though there is one great difference4 ,from beneath those of the ,earwig project two small leathery pieces which are absent in the ,beetle4 ,these pieces are not1 as one might imagine1 at the tips of the wings1 but on the front margin1 about halfway down1 and is indicated in the illustration by the shading between the extremity of the wing-case and the crease-mark at a4 ,illustration3 ,,fig4 #ch4--;,earwig 7male74 ,from the illustration we may understand how the ,earwig opens and closes its wings4 ,from the point a veins1 which are thickened about halfway down1 radiate to the hinder edge of the wing1 and a little beyond the thickening they are connected by a vein which runs parallel with the hinder edge4 ,these radiating veins are brought together1 so that there is a fan-like closing1 like that of the ,cockroach1 but from a different centre4 ,the wing is then folded back at the place where the veins are thickened1 and then there is a second transverse fold at the point a1 so that the only part of the wing now visible is the leathery patch1 which projects beyond the wing-case when the wing is tucked away4 ,it is not difficult to unfold the wing of a dead specimen1 under water1 using a needle and fine brush4 ,mr4 ,e4 ,a4 ,butler#be recommends a simple but excellent plan for unfolding and preserving the wing1 by gumming it1 with the upper surface downwards1 to a piece of card1 and gradually unfolding it and fastening it down4 ,this is not so easy as it may seem1 but with patience and perseverance success will be obtained2 and a similar method may be adopted with the wings of other ,insects1 which may be mounted in this way without any trouble4 ,thus they may be easily preserved for examination at a future time1 or for comparison with the wings of other ,insects4 ,it is rather remarkable that an insect like the ,common ,earwig1 which very rarely takes to flight1 should have such a complex method of folding its wings4 ,dr4 ,sharp says that though the ,earwig #8is scarcely surpassed in numbers by any ,british insect1 yet it is rarely seen on the wing4 ,it is probable that the majority of individuals of this species may never make use of their organs of flight1 or go through the complex process of folding and unfolding them4' ,let us choose our next example from the ,leaping ,orthoptera4 ,they may be distinguished at a glance from their relatives that run1 but do not leap1 by the peculiar structure of the third pair of legs4 ,these are much longer and stouter than the other two pairs1 and the thigh is very muscular4 ,this insect is a very good type of the family ,locustidae1 to which1 however1 none of the insects popularly called #8locusts' belong4 ,they are included in another family 7,acridiidae71 where the common ,british ,grasshoppers are also placed4 ,the ,locustids and the true locusts may be distinguished by the difference in their antennae3 in the latter these organs are short1 in the former they are very long and delicate4 ,the ,great ,green ,grasshopper 7,locusta viridissima7 7,fig4 #ci7 is fairly common all over the country1 but often escapes observation from the fact that its hue corresponds so nearly to that of the foliage on or among which it lives4 ,one specimen taken in a ,devonshire lane gave me a great deal of trouble before it was secured and transferred to a small tube4 ,it was perched on a leaf when ,i first saw it1 and as ,i approached it leaped away4 ,though ,i was certain it had not gone far1 it was some little time before ,i discovered it1 and got near enough to grasp leaf and insect1 in time to prevent the latter from taking another jump4 ,this insect may be kept alive in confinement for a considerable time1 and will do fairly well on a diet of leaves and fruit1 though it will not refuse an occasional meal of flesh4 ,dr4 ,sharp says that a specimen in confinement #8mastered a humble-bee1 extracted with its mandibles the honey-bag1 and ate this dainty1 leaving the other parts of the bee untouched4' ,it is said that if two be placed together in a box they will fight most desperately1 and that the victor will make a meal off the body of its victim4 ,de ,geer witnessed a case of this kind in a closely allied species that is found in ,sweden4 ,its specific name signifies #8wart-eater1' and commemorates the fact that the peasants incite these insects to bite their warts1 firmly believing that warts once bitten speedily disappear1 and do not grow again4 ,westwood says that one of these insects actually devoured part of its own leg that had been broken off accidentally4 ,when the creature was seen at night the detached leg was whole2 in the morning about half of it had been eaten4 ,illustration3 ,,fig4 #ci4--;,great ,green ,grasshopper 7female74 ,it is well to get specimens of male and female insects4 ,we shall require the former in order to examine the sound-producing apparatus1 which the females do not possess2 and the latter for the sake of the ovipositor--a long scimitar-like organ by means of which the eggs are deposited4 ,let us take the female first4 ,the length1 including the ovipositor1 is a little under two inches1 and the antennae will measure about as much more4 ,the wing-cases do not lie flat upon the back1 as do those of the ,cockroach1 but in a slanting position1 like the sides of a roof1 forming a ridge in the centre4 ,the head is not bent back1 as in the ,cockroach1 nor does it project in front1 as in the ,beetles1 but the front is almost vertical4 ,the armature of the mouth is strong1 and of the same pattern as that of the ,cockroach4 ,the hood--so the upper covering of the thorax is called--is of a peculiar shape1 somewhat like that of a saddle4 ,the wing-cases and wings1 with their folding1 will offer little difficulty4 ,next we may examine the cerci1 and contrast them with those of the ,cockroach and with the forceps of the ,earwig4 ,last of all1 the ovipositor must be examined1 and its structure made out1 so far as the means at our command will allow4 ,apparatus of this kind for placing eggs in positions favourable to their development is by no means confined to these insects1 for examples may be found in other ,orders4 ,sirex1 the so-called ,tailed ,wasp1 has a long straight one1 which is often supposed to be a sting1 and the insect itself is not unfrequently taken for a gigantic wasp or hornet4 ,when the ovipositor of our subject is looked at with the unassisted eye1 it appears to consist of two curved blades placed side by side1 with an internal groove on each4 ,the apparatus1 however1 is not quite so simple3 it is made up of six chitinous rods1 of which four--the two above1 and the two central ones--are developed from the ninth segment of the abdomen1 while the two lower ones spring from the eighth4 ,it is not difficult to test these statements4 ,specimens are plentiful2 and as the ovipositor in this insect is large1 and easily broken up into its component parts1 it may well serve as an introduction to the study of these organs in other ,insects--the ,saw-flies1 for example4 ,when the insect is about to deposit her eggs1 she selects a spot where the soil is light1 and bending the ovipositor nearly at a right angle to her body1 thrusts it into the ground as far as possible4 ,then1 by a muscular effort1 the plates of the ovipositor are separated1 and several eggs travel down the passage formed by the central pair of rods into the hole4 ,this is repeated time after time1 till the operation of egg-laying is completed4 ,this takes place in the autumn1 and the young emerge from the eggs in the spring4 ,when they come out they are tiny copies of the adults2 but they do not acquire wings till after several months4 ,the ovipositor of the female appears after the second moult1 and till this organ is developed no difference is apparent between the young insects4 ,the chief interest of the male insect lies in its wings1 for the first pair 7the tegmina7 are the organs with which it produces its #8love-songs4' ,kirby comments on the fact that ,lichtenstein1 in the ,linnaean ,transactions 7iv4 #ea71 #8draws attention to the eye-like area in the right wing-case of the males of this genus1' adding that that author seemed #8not to be aware that ,de ,geer had noticed it before him1 as a sexual character2 and also1 with good reason1 supposed that it assists these animals in the sounds they produce4' ,this is how ,de ,geer 7,mmoires1 iii4 #dbi7 describes the sound-producing apparatus of the ,great ,green ,grasshopper3 #8,in our male grasshoppers1 in that part of the right elytron which is folded horizontally over the trunk1 there is a round plate of very fine transparent membrane1 resembling a little mirror or piece of talc1 of the tension of a drum4 ,this membrane is surrounded by a strong and prominent nervure1 and is concealed under the fold of the left elytron1 which has also several prominent nervures answering to the margin of the membrane or ocellus4 ,there is every reason to believe that the brisk movement with which the grasshopper rubs these nervures against each other produces a vibration in the membrane1 augmenting the sound4 ,the males in question sing continually in the hedges in the months of ,july and ,august1 especially towards sunset1 and part of the night4 ,when any one approaches they immediately cease their 8song40' ,it is probably unnecessary to do more than remark that the noises made by ,insects do not correspond to the voices of the higher animals4 #8,for no insect1 like the larger animals1 uses its mouth for utterance of any kind3 in this respect they are all perfectly mute2 and1 though incessantly noisy1 are everlastingly silent#bf4' ,our plan with these wings is to first verify the fact of their bearing these talc-like spots1 the serrated nervures on the right and the rudimentary file on the left elytron4 ,the sound is produced by rubbing the base of the left elytron against that of the right4 ,a recent author compares this insect to a fiddler1 and says that the left tegmen is the bow and the right the fiddle4 ,the last point to examine is the ear4 ,it seems strange to say that these insects have ears in their legs2 but though some of the older entomologists regarded these structures in the tibiae of the first pair of legs as nothing more than resonators or sound-boards to intensify their chirping1 there is no doubt that they are really organs of hearing4 ,much interesting information on this subject will be found in ,sir ,john ,lubbock's ,senses of ,animals4 ,illustration3 ,,fig4 #dj4--,tibial ear of ,great ,green ,grasshopper4 ,these oval patches are plainly distinguishable by the unassisted eye1 and correspond in function to the tympanum or drum of the human ear4 ,the air-supply to the tibiae is distinct from that of the rest of the body1 and is derived from a large orifice on each side of the first segment of the thorax4 ,these orifices may be seen by removing the #8hood4' ,indeed1 they cannot escape observation4 ,from these orifices an air-tube passes to each leg1 dividing into two branches in the tibia and reuniting below the drums4 ,dr4 ,sharp#bg says that #8although the tibial ears of the ,locustidae are very perfect organs1 there is great difficulty in deciding on the exact nature of their functions4 ,they would appear to be admirably adapted to determine the precise locality from which a sound proceeds 444 for the legs can be moved in the freest manner in every direction1 so as to bring the drum into the most direct line of the vibrations4 ,but as to what kinds of vibrations may be perceived1 and the manner in which they may be transmitted to the nerves1 there is but little evidence4' ,the next ,order from which we shall choose examples will be the ,hemiptera1 containing the ,land and ,water ,bugs and some other forms4 ,our chief concern1 however1 is with the ,water ,bugs4 ,in this ,order the metamorphosis is incomplete2 the mouth is adapted for sucking the juices of plants and animals2 and there are usually four wings4 ,in the ,land and ,water ,bugs1 part of the fore wings is harder than the hind wings2 in the other winged members of the ,order both pairs of wings are membranous4 ,the front wings are called hemelytra or halfelytra1 to distinguish them from the elytra or wing-cases of ,beetles1 which are chitinous throughout4 ,fig4 #da shows the hemelytron and hind wing of a ,land ,bug1 and the names given to the different parts of the front wing4 ,illustration3 ,,fig4 #da4--;,a ,land ,bug 7magnified74 a1 corium2 b1 clavus2 c1 membrane4 ,the ,water ,scorpion 7,nepa cinerea7 is not difficult to procure1 or to keep in confinement when it is caught4 ,it would be straining language to call it a handsome creature1 yet it well deserves careful study1 on account of the wonderful modification of the first pair of legs1 and it is from the resemblance of these to the pedipalps of the scorpion that the insect derives its popular name4 ,its length is about an inch and a quarter1 from the tip of the beak1 or rostrum1 to the end of the breathing-tube4 ,its greatest width is a little over a quarter of an inch 7,fig4 #db74 ,the general hue harmonizes well with the mud1 but the upper surface of the abdomen is a warm red1 #8and is thick set with hair1 so as to afford a very agreeable sight4' ,illustration3 ,,fig4 #db4--,water ,scorpion4 ,it is extremely common in shallow pools1 and its favourite haunt is near the shore1 where it will lie1 almost buried in the mud1 with its raptorial legs elevated1 ready to seize on any passing insect1 and its breathing-tube just pushed through the surface-film4 ,i learnt this habit of the insect on the first occasion on which ,i tried to collect specimens of it4 ,i had been told that a certain piece of water swarmed with ,water ,scorpions4 ,this1 ,i afterwards found1 was quite correct2 but though ,i worked the pond from end to end1 a single specimen was all that rewarded my labour4 ,whilst transferring the insect from the net-tube to the bottle for transport1 a stranger joined me1 and kindly volunteered his assistance4 ,he had no collecting tackle1 but in about a quarter of an hour he brought at least a dozen good specimens in the bottle he had borrowed4 ,it was natural to inquire to what his success was due4 ,he told me that it was his first attempt at collecting1 but that just before joining me he had noticed the ends of the breathing-tubes sticking out of the water4 ,this excited his curiosity1 and on moving the mud with his walking-stick1 the insects were seen to crawl away slowly4 ,when he saw me transfer the ,water ,scorpion from the net-tube to the bottle1 he immediately recognized it4 ,then he courteously offered his help1 for which1 of course1 ,i was grateful4 ,we may keep the ,water ,scorpion alive for a considerable time in a small bottle of water1 in which is some growing weed4 ,if we watch it moving about1 we shall see that the front legs are used for locomotion as well as for seizing prey4 ,some authors doubt this4 ,any one may settle the question for himself1 if he will put one of these insects into a small bottle with plenty of weed4 ,generally1 however1 the insect uses only the second and third pairs for walking1 the first pair being raised and directed forward1 with the tarsus bent at an angle 7,fig4 #db74 ,even when it does use its front legs for locomotion1 the action is not that of walking2 the insect employs these limbs to pull itself along in a sort of #8hand-over-hand' fashion1 but on a level surface it uses the first pair in the same way as it does the other two pairs4 ,its habit of burying itself in the mud may also be watched with very little trouble4 ,a common pudding-basin will make an excellent aquarium for this purpose4 ,the bottom is to be covered with garden mould and vegetable dbris1 mixed with a few stones4 ,the whole mass should be arranged unevenly1 so that when water is added it may not form one sheet1 but a series of small shallow pools4 ,very little duckweed will serve to keep it sweet4 ,it only remains to drop in the ,water ,scorpion4 ,before long it will accommodate itself to its new surroundings1 and so bury itself that it will be no easy task to discover it4 ,an aquarium of the kind described stands at present on my writing-table4 ,many have been the inquiries as to what kind of creature lived therein2 and more than one old hand at collecting has failed to find the insect4 ,it is always safe to look round the sides of the basin for the breathing-tube2 if it is not detected in this situation1 a glance along the surface of the tiny pools will probably show a break in the film4 ,the ,water ,scorpion will not be far off4 ,that the insect really does cover itself with mud may be demonstrated by transferring it from the aquarium described to any shallow vessel1 and allowing a fine stream of water--say1 from a dipping-tube--to fall gently on it4 ,the mud will be washed away1 and in a few seconds will settle at the bottom4 ,it is well to keep such an aquarium covered1 for the ,water ,scorpion has no mean power of flight4 ,a circular plate of glass1 which may be bought for a few pence1 makes the best cover1 but a piece of fine muslin fastened round the rim of the basin will do4 ,swammerdam says1 #8,these ,water ,scorpions live all the day in the water1 out of which they rise about the dusk of evening into the air1 and so flying from place to place1 often betake themselves in quest of food to other waters4' ,then follows a deduction which shows how far he was in advance of his time3 #8,this affords us a satisfactory reason for the great number of insects that immediately appear in the smallest collections of water1 since they may very well get thither when it is dark1 so that the opinion which ascribes to putrefaction the power of forming insects1 c41 must1 by this instance of the ,water ,scorpion's nocturnal transmigrations1 appear more and more frivolous and unnecessary4' ,illustration3 ,,fig4 #dc4--;,a4 ,water ,scorpion4 a1 rostrum2 b1 wing-cases2 c1 wings2 d d1 second and third pairs of legs2 e1 raptorial legs 7the first pair72 f1 spine forming breathing-tube2 g1 parasitic mite4 ,b4 ,portion of an oviduct containing eggs 7magnified74 ,c4 ,an egg 7magnified74 ,d4 ,parasitic mite4 a1 head2 b1 eyes2 c1 legs2 d d1 legs 7seen from under surface74 7,after ,swammerdam47 ,no larva or other animal that is of any value should be kept in the same aquarium with the ,water ,scorpion4 ,dr4 ,hill1 who annotated the ,english edition of ,swammerdam1 says1 #8,there is not perhaps in all the animal creation so outrageous or fierce a creature against those weaker than itself as the ,water ,scorpion4 ,it destroys1 like the wolf among sheep1 twenty times as many as its hunger requires4' ,the ,rev4 ,g4 ,c4 ,bateman placed one in a saucer with a tiny minnow2 #8but no sooner did the little fish swim within reach of the fore-legs of the scorpion than it was seized by them1 and pressed against the hungry creature's rostrum4' ,it seems to be particularly fond of ,asellus1 the water woodlouse4 ,i have often taken dead specimens of this crustacean1 sucked completely dry1 from between the raptorial legs of the insect4 ,one specimen was so thoroughly cleaned out that it was mounted just as it was1 the only preparation being a brief soaking in spirit4 ,in examining the head the eyes may be readily distinguished1 and on pressing the rostrum or beak with a needle1 the proboscis will be forced out1 just as one may force out the sting by pressing the abdomen of a bee or a wasp4 ,in this group the antennae are three-jointed and concealed4 ,when one begins to look for these organs he will probably come to the conclusion that the concealment is highly effectual4 ,a very simple method of finding them in a spirit specimen is to take the insect between the thumb and index finger of the left hand1 holding it up to the light in such fashion as to keep the first pair of legs well clear of the head4 ,then1 with a needle held in the right hand1 raise the thorax till it lies in the same plane as the body4 ,each antenna lies in a groove beneath the eye4 ,gentle manipulation with the needle will lift them out1 so that they may be clearly seen1 not only with the hand magnifier1 but with the unassisted eye4 ,or the insect may be pinned down under water instead of being held in the hand1 and the antennae lifted or brushed out of the groove4 ,it will greatly simplify matters if1 before attempting to raise the wings1 the fact is borne in mind that the tip of the right wing-case lies over that of the left4 ,it is perhaps as well to remove the wing-case altogether by inserting a needle under it1 and gently raising it1 using a little pressure in an outward direction4 ,it will then be quite time to raise the wing and to see the method of folding and unfolding4 ,illustration3 ,,fig4 #dd4--,raptorial leg of ,water ,scorpion4 ,in ,fig4 #dd we have a representation of the raptorial 7front7 leg of this insect4 ,this leg should be compared with the legs of other ,insects--not in pictures only1 but in actual specimens--that we may see how1 while the general plan is preserved1 different joints are modified to suit the special function of this limb--that of taking prey4 7,see also ,fig4 #dc47 ,the thigh 7f7 is the largest joint1 for the obvious reason that it contains the muscles that work the tibia and tarsus1 which together form a kind of knife-blade1 shutting down into a groove in the thigh1 which may very well be compared to the handle of a pocket-knife4 ,this description1 however1 is not to be taken on trust4 ,it is not enough to read about the groove3 we must see it for ourselves1 raise the #8knife-blade' from the groove1 and press it down again1 and pass the needle along the groove4 ,if we examine the interior of the groove1 we shall find that there is a projection along the bottom1 so that a cross section would appear like this--,wimage4 ,the inner portion of the tibia is also grooved2 so that when once the prey is seized by this powerful limb1 it has no chance of escape4 ,the tarsus 7tar7 is not clearly distinguished from the tibia 7tib7 in the engraving1 but it may be distinctly seen as a claw-like appendage in a living or dead specimen4 ,the breathing-tube remains to be examined4 ,it may be detached from the body for more convenient manipulation4 ,when this is done1 the tube will be seen to consist of two pieces1 each grooved on the inner side and set with hairs1 which1 as they interlock1 prevent the entrance of water4 ,a somewhat similar arrangement occurs in the proboscis or tongue of butterflies4 ,there is perhaps a closer parallel in the antennae of the masked crab1 which1 under certain conditions1 form a kind of breathing-tube1 each antenna being joined to its fellow by the hairs with which it is set4 ,there are two other ,water ,bugs which lend themselves to our purpose very well4 ,each is popularly called ,water ,boatman1 though that name is better confined to ,notonecta1 because the insects of this genus #8row themselves about on their backs with their long feathered legs4' ,in the ,united ,states they are called ,water ,cicadae1 from the shrill noise they make1 probably by rubbing the fore-legs together4 ,illustration3 ,,fig4 #de4--,water ,boatman4 ,in ,fig4 #de the ,water ,boatman 7,notonecta glauca7 is represented as seen from above--a position in which we shall rarely discover it1 if we keep it in a small aquarium4 ,in ,fig4 #df the same insect is shown swimming on its back1 or in the position it assumes when taking in a supply of air4 ,the end of the abdomen and the tips of the feet rest against the surface-film2 and at the slightest alarm a vigorous stroke of the last pair of legs sends the insect to a place of safety4 ,from the way in which these insects habitually swim1 ,mouffet came to the conclusion that it was probable men learned the art of swimming on their backs from them4 ,illustration3 ,,fig4 #df4--,water ,boatman swimming4 ,active as the ,water ,boatman is1 it often falls a victim to the ,water ,scorpion1 if both are kept in the same aquarium4 ,i learnt this fact by experience1 for having put two ,water ,boatmen into a small tank in which was a ,water ,scorpion1 ,i found both the former dead in the morning4 ,it was evident that their destroyer had had a good meal4 ,the only point to which attention need be called in examining the ,water ,boatman is its method of taking in a supply of air4 ,in looking at a dead specimen we shall see a ridge or keel running down the middle of the under side of the abdomen1 and fringed with hair on each side4 ,a similar fringe runs along each side of the abdomen1 thus forming two passages along which the air taken in at the end of the body is conveyed to the spiracles1 the largest of which are on the thorax4 ,corixa 7,fig4 #dg7 swims with its back uppermost1 and when kept in the aquarium may generally be seen foraging for small creatures--larvae or worms--among the sediment at the bottom4 ,bateman1 who kept a number of these insects1 says that he fed his specimens on garden worms and pieces of raw meat4 ,mine have always foraged for themselves1 and done very well without feeding4 ,they may often be seen to rub the short fore-legs alternately across the front of the head1 probably for the purpose of producing a call-note4 ,i have often watched them at this practice1 but have never been able to detect any sound4 ,the defect is evidently in my sense of hearing1 for the sounds rest on undoubted authority1 and are coincident with the rubbing of the fore-legs across the head4 ,illustration3 ,,fig4 #dg4--;,corixa1 with wings expanded4 ,where sound-producing organs exist it is more than probable the capacity for receiving sound-impressions also exists4 ,graber made some interesting experiments to test the sense of hearing in ,corixa4 ,his results are thus summarized by ,sir ,john ,lubbock#bh3 #8,he placed some ,water ,boatmen 7,corixa7 in a deep jar full of water1 at the bottom of which was a layer of mud4 ,he dropped a stone on the mud1 but the insects1 which were reposing quietly on some weeds1 took no notice4 ,he then put a piece of glass on the mud1 and dropped the stone on to it1 thus making a noise1 though the disturbance of the water was the same4 ,the ,water ,boatmen1 however1 at once took to flight4' ,,chapter ,,iv ,,spiders1 ,,mites1 ,,and ,,myriapods ,in this chapter we shall take examples from two ,classes--the ,arachnoidea and the ,myriapoda4 ,to the first-named ,class belong also the ,scorpions1 which1 with the ,book ,scorpions1 the ,harvestmen1 and some others1 may be neglected here4 ,this will leave us only the ,spiders and ,mites to deal with4 ,every one knows a ,spider when he sees one1 though not every one can give offhand a definition that shall include the whole ,order4 ,let us endeavour to express their characters in simple terms1 keeping in mind the definition of head1 thorax1 and abdomen in ,chapter ,,ii4 ,in ,spiders the head and thorax are joined together in one unsegmented portion1 called the cephalothorax1 and this is connected with the abdomen1 which is also unsegmented1 by a more or less slender stalk or peduncle4 ,so that while ,insects have three regions1 ,spiders have but two4 ,we may express the difference thus3 ,insects head1 thorax abdomen4 ---v---_/image ,spider cephalothorax abdomen4 ,the cephalothorax bears six pairs of appendages 7,fig4 #dh;,a74 ,taking these in order1 there are-- #a4 ,a pair of falces 7an71 representing the antennae of insects4 ,these have a movable claw-like joint at the extremity1 perforated so as to convey into a wound the secretion from the poison-glands4 #b4 ,a pair of five-jointed pedipalps 7p71 sometimes called maxillary palpi1 from the fact that the parts whence they spring correspond to the maxillae of insects 7,fig4 #ba;,a1 d74 ,in the female the last joint terminates in a claw2 in the male this joint is specially modified for sexual purposes 7,fig4 #dh;,b74 #c4 ,four pairs of walking legs1 of which only the coxae 7c7 are shown in the diagram4 ,the two front legs are often used as organs of touch4 ,breathing is carried on by chambered air-tubes or lung-sacs1 and in all our ,british ,spiders 7with the single exception of the native ,trap-door ,spider1 which1 by the way1 does not make a trap-door7 there are also air-tubes resembling those of ,insects4 ,the lung-sacs open to the external air by stigmata 7st7 on the abdomen1 while the ordinary air-tubes open near the spinnerets 7sp71 the organs employed in the production of the silky threads from which are formed webs1 nests1 egg-bags1 and ropes4 ,by means of these threads1 spiders drop from their webs to the ground1 construct flying bridges from one point to another1 and even in some sort travel through the air4 ,spiders live upon the juices of their prey1 which are drawn up into the stomach by means of a suctorial apparatus at the end of the gullet4 ,the young1 when they leave the egg1 resemble their parents in all respects but size--that is1 they undergo no metamorphosis4 ,the eyes of spiders are simple1 and six or eight in number4 ,these vary much in size and relative position1 and furnish characters of great importance in classifying species4 ,those of the ,hunting ,spiders1 which make no web1 but pursue or spring upon their prey1 are usually arranged in three rows2 while those which make webs for the capture of prey have the eyes in a double row4 ,in all cases they are on the front part of the upper surface of the cephalothorax4 ,illustration3 ,,fig4 #dh4--;,a4 ,scheme of under surface of ,wolf ,spider 7female74 ,b4 ,pedipalp of male 7enlarged74 ,for other references1 see text4 ,the ,common ,garden ,spider 7,epeira diadema7 is a very good subject1 and there can be no difficulty in procuring any number of specimens4 ,the smallest garden will be sure to yield a plentiful supply2 and even if we have no garden1 a very superficial search among the hedgerows will give us as many as we can possibly want4 ,every one knows this spider1 and the beautifully regular web which it makes4 ,first of all1 what one may call the outline of the web is spun--strong threads stretching from point to point1 to which are attached lines radiating from a common centre4 ,this may be represented diagrammatically by drawing a circle and producing radii from the centre to the circumference in all directions1 or by making a rectangular figure and drawing lines to the boundaries from the point where the diagonals intersect4 ,it must not1 however1 be supposed that the outline of the web is of a regular form4 ,in this respect the spider adapts itself to circumstances1 and spins a greater or less number of supporting threads1 as may be necessary4 ,illustration3 ,,fig4 #di4--;,garden ,spider and ,web4 ,then the spiral is made 7,fig4 #di7 from the centre to the circumference4 ,the first few turns are of the same character as the radial lines2 but all the rest of the short lines forming the spiral1 and connecting the radial lines1 are coated with a viscid secretion1 which is the essential part of the snare2 for the victims are really limed like birds on a twig1 not entangled in the threads4 ,it is well to test the character of the different parts of the spiral1 not only by touch1 which is convincing enough1 but with pocket lens4 ,our low powers will not give such results as are shown in ,fig4 #ej1 but we shall have no difficulty in distinguishing the sticky parts from those not coated with the secretion4 ,illustration3 ,,fig4 #ej4--;,a ,adhesive ,threads of ,spiral4 ,b4 ,non-adhesive ,radial ,threads4 ,it may be doubted whether all the ,spiders of this genus make the spiral in the same way1 for observers differ in their description of what they have seen4 ,some say that a non-adhesive spiral from centre to circumference is first made1 and that the spider then moves #8in a closer spiral from the circumference inwards1 biting away the former spiral1 replacing it by another1 which is viscid and adhesive#bi4' ,dr4 ,butler1 on the other hand1 who #8watched spiders for months together1 petting1 feeding1 and trying experiments with them every morning1' after describing the making of the first and non-adhesive part of the spiral1 says1 #8,this line is not carried to the boundary1 but at some distance from the centre a second is commenced1 formed of extremely viscid silk1 upon which the gummy secretion is distinctly visible1 with the aid of a lens1 in the form of closely approximated globules of amber-coloured glue4 ,it is said that when the viscid lines are completed the spider cuts away the unadhesive lines1 but this ,i have never observed#cj4' ,my own observations lead me to believe that ,dr4 ,butler is correct in his description4 ,though ,i have often watched1 ,i have never seen a spider #8biting' away any part of its web1 nor would the falces appear to be adapted for such an operation4 ,they are piercing1 not cutting1 weapons4 ,the spider may be watched at leisure1 if put into a bottle of moderate size1 the top of which should be covered with muslin or calico to prevent escape4 ,here it is fairly easy to bring the pocket lens into play1 and to distinguish the different parts of the animal4 ,the eyes1 and their arrangement1 should be particularly noticed4 ,illustration3 ,,fig4 #ea4--;,anchorage of ,web4 ,blackwall1 in support of the position that in making their webs spiders are guided by touch rather than sight1 says1 #8,various species1 when confined in spacious glass jars placed in situations absolutely impervious to light1 construct nets which do not exhibit the slightest irregularity of plan or defect of structure#ca4' ,my specimens have always been kept in the light1 and in small bottles rather than spacious jars1 but ,i have never seen spiders attempt to make a geometrical web under such conditions4 ,a bottle which for some months served as a prison-house for a ,garden ,spider now stands on my writing-table4 ,its sides are marked by hundreds of #8anchorages'--but the threads cross and recross1 forming in some parts a kind of sheet1 and in others a tangled mass4 ,some of these threads must have been covered with viscid secretion1 for flies were limed1 and so fell a prey to the spider4 ,their dried skins are dotted about among the threads1 and the spider itself perished long ago from cold4 ,but ,i keep the bottle as a curiosity1 to show that these spiders do not always make geometrical webs4 ,when one has a ,garden ,spider in a bottle1 it may be observed to practise a curious and very effective method of disabling its prey4 ,if a bluebottle or any other large fly be dropped and entangled among the threads1 the spider will envelop it in a sheet of web4 ,this is how ,blackwall describes the operation3 #8,causing the victim to rotate by the action of the third pair of legs and the palps1 the first pair of legs also being frequently employed in a similar manner1 they extend the spinners laterally1 and applying to them alternately the sustentaculum of each posterior leg1 they seize and draw out numerous fine lines in the form of a fillet1 which they attach to their revolving prey1 and thus involve it in a dense covering of silk from one extremity to the other4 ,by means of this stratagem they are capable of overcoming formidable and powerful insects1 such as wasps1 bees1 and even large beetles#cb4' ,the operation does not occupy much time2 in a very few minutes the fly is swathed in a silky covering as completely as an ,egyptian mummy in its linen folds4 ,of course resistance1 much less attack1 is out of the question1 and when it is thus rendered powerless for harm the spider proceeds with its meal4 ,the sustentaculum--or support--is a strong movable spine near the end of the tarsus1 on the under side of each of the last pair of legs4 ,these spines act in opposition to the claws1 and thus these animals are enabled to hold with a firm grasp such lines as they have occasion to draw from their spinners with the feet of the hind legs1 and such also as they design to attach themselves to4 ,with regard to this method of swathing prey1 ,hudson#cc says of an ,argentine spider1 #8that its intelligence has supplemented this instinctive procedure with a very curious and unique habit4 ,the ,pholcus1 in spite of its size1 is a weak creature1 possessing little venom to dispatch its prey with1 so that it makes a long and laborious task of killing a fly4 ,a fly1 when caught in a web1 is a noisy creature1 and it thus happens that when the ,daddy longlegs--as ,anglo-,argentines have dubbed this species--succeeds in snaring a captive1 the shrill outrageous cries of the victim are heard for a long time--often for ten or twelve minutes4 ,this noise greatly excites other spiders in the vicinity1 and presently they are seen quitting their webs and hurrying to the scene of conflict4 ,sometimes the captor is driven off1 and then the strongest or most daring spider carries away the fly4 ,but where a large colony are allowed to continue for a long time in undisturbed possession of a ceiling1 when one has caught a fly he proceeds rapidly to throw a covering of web over it1 then1 cutting it away1 drops it down and lets it hang suspended by a line at a distance of two or three feet from the ceiling4 ,the other spiders arrive on the scene1 and after a short investigation retreat to their own webs1 and when the coast is clear our spider proceeds to draw up the captive fly1 which is by this time exhausted with its struggles4' ,in this connexion ,hudson notes that spiders are attracted by the sound of the vibration of a string or wire1 thinking it made by an insect that has been caught2 and he says that the stories of tame spiders are founded on a misunderstanding of the motive that brings the animal down4 ,we may well doubt if spiders are attracted by music1 but that some spiders possess a sense of hearing1 or something analogous thereto1 seems to be proved by the existence of stridulating organs in certain members of the group4 ,illustration3 ,,fig4 #eb4--;,foot of ,garden ,spider4 ,illustration3 ,,fig4 #ec4--,spinnerets of ,garden ,spider4 ,two other points remain to be noted4 ,the feet should be examined1 for their structure throws some light on the way in which the ,garden ,spider runs so securely to and fro on the radial lines4 ,one of the legs of a dead specimen should be detached1 and its armature of spines and hairs noted4 ,the foot is armed with three stout claws1 which are pectinated--that is1 toothed like a comb1 and beneath them are smaller ones1 sometimes described as toothed hairs4 ,it will be easy to understand what a secure foothold these claws give the animal as it runs backwards and forwards over the radial lines2 for if the web be shaken by the wind or designedly its owner can take a firm hold with each foot1 and thus have eight separate points of attachment4 ,an inch hand lens is quite sufficient to give a general idea of the hairy and spinous clothing of the legs and the position of the claws2 but to see the teeth a higher power--a half-inch--will be necessary4 ,it is a good plan to choose a freshly killed specimen for the examination of its spinnerets4 ,if the spider is laid on its back in a glass dish1 gentle pressure on the abdomen away from the cephalothorax will cause the material secreted by the spinning-glands to ooze out4 ,this1 however1 cannot be done if the specimen has been for some time in spirit4 ,we shall be able to make out six tubes 7four of them larger than the other two7 grouped round the anal aperture2 but1 for the present1 we must take for granted the fact that these are made up of a number of smaller tubes1 so that the end of each spinneret is not unlike the rose of a watering-can4 ,a good half-inch will give some indications of this rose-like appearance4 ,the ,jumping ,spider 7,salticus scenicus7 belongs to a family the members of which make no web or snare for the capture of prey1 but trust for their food-supply to their skill in stalking flies and other insects1 which they capture by a sudden spring4 ,it is from this habit that the type-genus and the family have received their scientific and popular names4 ,the common ,british species is extremely abundant1 and wherever flies are plentiful these spiders will not be very far off4 ,this is the case not only in the country1 but also in ,london and other large towns4 ,it is a noticeable spider from its coloration--black marked with white4 ,the eyes are eight in number2 though the artist in our illustration has only represented four4 ,the centre two of the front are the largest of all1 and have been compared not inaptly to bull's eyes4 ,two others are placed on each side of the cephalothorax1 so that the eyes form1 roughly1 three sides of a square1 and the central eyes in the lateral lines are the smallest4 ,we may represent them thus image1 while the eyes of the ,garden ,spider are disposed in this fashion image4 ,illustration3 ,,fig4 #ed4--;,jumping ,spider4 7,line shows natural size47 ,illustration3 ,,fig4 #ee4--;,falces of ,male ,jumping ,spider4 ,it requires some little practice to detect the eyes of spiders and to remember their position in the different genera1 but by examining every spider met with1 and consulting some handbook to the group1 one will soon be able to determine the commoner ,british species4 ,with a couple of needles we may remove the falces 7,fig4 #ee7 for examination2 and there is no difficulty in mounting them1 as shown in the cut1 on a piece of card1 so that they may be compared with the same weapons in other species4 ,for example1 the falces of the ,garden ,spider differ from those of the ,jumping ,spider in that they are short and stout1 and the teeth on the basal joint are more in number4 ,the following account of the habit of this spider in capturing prey is from ,kirby and ,spence's ,introduction to ,entomology 7ed4 #ahgj1 p4 #dec73--#8,when these insects spy a small gnat or fly upon a wall1 they creep very gently towards it with short steps1 till they come within a convenient distance1 when they spring upon it suddenly like a tiger4 ,bartram observed one of these spiders that jumped two feet upon a humble-bee4 ,the most amusing account1 however1 of the motions of these animals is given by the celebrated ,evelyn in his ,travels4 ,when at ,rome1 he often observed a spider of this kind hunting the flies which alighted upon a rail on which was its station4 ,it kept crawling under the rail till it arrived at the part opposite to the fly1 when stealing up it would attempt to leap upon it4 ,if it discovered that it was not perfectly opposite1 it would immediately slide down again unobserved1 and at the next attempt would come directly upon the fly's back4 ,did the fly happen not to be within a leap1 it would move towards it so softly1 that its motion seemed not more perceptible than that of the shadow of the gnomon of a dial4 ,if the intended prey moved1 the spider would keep pace with it as exactly as if they were actuated by one spirit1 moving backwards1 forwards1 or on each side without turning4 ,when the fly took wing1 and pitched itself behind the huntress1 she turned round with the swiftness of thought1 and always kept her head towards it1 though to all appearance as immovable as one of the nails driven into the wood on which was her station3 till at last1 being arrived within due distance1 swift as lightning she made the fatal leap and secured her prey4' ,this spider employs a clever precaution against falling1 when about to spring upon its prey4 ,it applies the end of the abdomen to the surface on which it stands1 and opening its spinnerets1 makes an #8anchorage' 7,fig4 #ef74 ,then1 by the act of springing1 it draws from the spinnerets a line attached to the spot from which it started4 ,this line is strong enough to support the spider in case it misses its prey4 ,illustration3 ,,fig4 #ef4--;,a4 ,foot or ,jumping ,spider4 ,b4 ,scopula4 7,much enlarged47 ,the foot of the ,jumping ,spider is extremely interesting1 and shows a very ingenious arrangement1 by means of which the animal can run with difficulty on smooth polished upright surfaces1 or retain its footing when it alights on such surfaces after a spring4 ,we can see this arrangement in ,fig4 #ef4 ,just behind the claws is a bundle of coarse hairs1 technically called a scopula1 or little brush4 ,from these hairs adhesive matter flows1 and in this fashion the spider literally sticks on4 ,with this brush of hairs may be compared the tarsal cushions of many flies1 and the adhesive hairs of ,dytiscus and other beetles 7see ,chap4 ,,ii7--though these last have a different function4 ,diving ,spiders 7,argyroneta aquatica7 are especially suitable for our purpose4 ,they are very common in most ponds1 and in some places are so abundant as to be almost a nuisance to the collector who is in search of other things4 ,three of them are represented in ,fig4 #eg4 ,one is swimming2 another is just entering the bell-shaped web under water2 and the third is just climbing out of the water on to the broad floating leaves of the water crowfoot4 ,illustration3 ,,fig4 #eg4--;,diving ,spiders4 ,de ,geer's account of these spiders is extremely interesting#cd1 and we may verify it for ourselves1 for these creatures may be kept without any trouble4 ,they certainly agree1 when a number are kept in captivity1 much better than do other spiders4 ,de ,geer kept several in the same aquarium1 and says that when they met they felt each other with their palps1 and opened their falces1 but he never saw them do any harm to each other4 ,i have kept them under similar conditions with the same result4 ,he tells us that these spiders spin under water a cell of strong1 close1 white silk1 the shape of which he compares to a skull-cap1 the half of a pigeon's egg1 or a diving-bell4 ,in ,september1 #agcf1 he first became acquainted with these creatures1 and kept one in an aquarium for four months4 ,it made its cell against the side of the aquarium1 and the top of it rose above the surface of the water4 7,this was due to its being inflated4 ,the web was not spun above the surface47 ,the walls of the cell were very thin1 but it was filled with air1 and the spider was resting inside1 head uppermost1 with its legs pressed against the body4 ,about three months later he found that the mouth of the cell was closed1 and the spider was comfortably settled in its winter quarters4 ,when pressure was applied the cell burst and the air escaped1 mounting up to the top in bubbles4 ,the spider made its way out1 and took an ,asellus that was offered1 and made a meal of it4 ,de ,geer then came to the conclusion that these cells under water were constructed for the purpose of affording the spider a retreat when the water was frozen over1 so that they could not come to the surface for a supply of air4 ,he found1 however1 by observation1 that they were also made in summer by both sexes4 ,in a cell of this kind the female deposits her eggs--from eighty to a hundred in number1 enclosed in a cocoon of white silk--and keeps guard over them1 with her head defending the entrance to the cell4 ,he succeeded in finding out the method by which the ,diving ,spider fills its cell with air4 ,he noticed that when the creature was moving about in the water1 its body was covered with a layer of air1 and that this air was renewed from time to time when the animal came to the surface and raised its abdomen above the water4 ,loaded1 so to speak1 with air in this fashion1 the spider descended1 and entered the cell backwards1 leaving an air-bubble4 ,having repeated this several times1 at last she removed all the water from the cell1 introducing in its place an equal quantity of air4 ,it is very easy to watch the ,diving ,spider making its dwelling under water1 and filling it with air4 ,first of all the web is woven in a bell or thimble shape between the sprays of water-weed1 or against the bottom or side of the aquarium4 ,it is curious to notice how practices that must be necessary when the creature is at liberty are continued in captivity where they are useless4 ,a web constructed in running water1 or even in a pond or ditch1 is liable to be swept away or to be emptied of air by a very slight current1 so its owner has recourse to a system of guys and supporting threads1 which are not required when the spider is safely housed in a small aquarium4 ,nevertheless1 the guys are made4 ,in an eight-ounce bottle ,i have now a male ,diving ,spider1 which has lived there for about seven months4 ,its cell is made between the whorls of a spray of milfoil1 and guy threads have been carried to no less than five whorls--two above and three below the opening4 ,now that it is filled with air1 the cell gleams in the water like a great bubble of quicksilver4 ,the air may be expelled by shaking or tilting the bottle1 and if the web be not damaged the spider will generally refill it with air1 though sometimes it prefers to make a new dwelling4 ,fig4 #eh shows the cell of a ,diving ,spider2 the white lines represent supporting threads attached to the water plants4 ,in examining dead specimens we shall find that1 contrary to what is usual1 the male exceeds the female in size4 ,i have a slide of a male1 with the legs spread out before and behind1 and the measurement from the claws of the first pair of legs to those of the fourth pair is #a inches4 ,the body is inch long4 ,the whole surface is more thickly clothed with hair than is the case with other spiders1 and the reason for this is obvious4 ,this hairy body-covering serves to carry down into the water a layer of air1 and the fringe of hair on the legs makes them efficient swimming organs4 ,illustration3 ,,fig4 #eh4--;,cell of ,diving ,spider4 ,the ,order of ,mites will yield us subjects for our pocket lens4 ,mites are related to ,spiders1 but form a distinct ,order4 ,like the ,spiders1 some are aquatic1 though the most of them live on land4 ,many are parasitic1 during the whole or part of their lives subsisting on the juices of their hosts3 the food of others consists of organic dbris1 and these seem to be of benefit to man1 since they act as scavengers4 ,if we turn to page #if we shall there find noted the points of difference in the arrangement of the main divisions of the body in ,insects and in ,spiders4 ,in ,mites the distinction between the cephalothorax and abdomen is lost1 and the body is more or less oval or globular4 ,in the perfect forms there are eight legs2 but some1 in their earlier stages1 have only six4 ,the mouth may be adapted for biting1 though it is usually suctorial4 ,in the ,cheese ,mites and some others breathing seems to be carried on through the skin1 for there are no air-tubes2 but in most ,mites air-tubes1 with two stigmata1 are present4 ,if we take a dip with the collecting-net in almost any pond we shall be pretty sure to capture some specimens of ,water ,mites of the genus ,hydrachna1 easily recognizable by their bright coloration1 their eight swimming legs thickly fringed with hair1 and their unceasing activity4 ,they may be kept in a bottle1 or other small vessel1 with some water-weed1 and will forage for themselves4 ,in ,fig4 #ei we shall see the points we have to look for in examining a ,water ,mite with a pocket lens4 ,there should be no difficulty in making out in the specimen all the details shown in the cut4 ,it may be that they will breed3 if so we should avail ourselves of the opportunity of watching their development4 ,their life-history is somewhat curious1 and is specially interesting from the fact that while ,swammerdam had some faint perception of the true meaning of what he saw1 ,de ,geer1 writing a hundred years later1 drew entirely wrong conclusions from similar observations4 ,it was left for ,dugs to clear up the matter in the ,annales des ,sciences ,naturelles1 #ahcd4 ,before summarizing the account of the ,french naturalist it may be well to quote what ,swammerdam and ,de ,geer have said on the subject3-- #8,there is nothing more remarkable in this insect the ,water ,scorpion than that it constantly appears covered with a prodigious number of nits of different sorts and sizes1 though perhaps we may with more reason consider them as so many little creatures1 which live and grow by sucking the ,scorpion's blood4 ,these are somewhat of an oblong figure1 approaching to round1 and have a shining1 and as it were bloated1 surface1 without any of the rings observable in most insects4 ,the neck is oblong and shaped like a pear1 with the small end sticking in the ,scorpion's body4 ,the colour of this insect is a mean between that of vermilion and purple2 and when it is pretty well grown there appears within it an elegant transparent spot or particle 7,fig4 #ei74 ,illustration3 ,,fig4 #ei4--,red ,water ,mite 7nat4 size1 and under surface magnified74 #8,this spot or particle induced me to consider with more attention this minute and hitherto unregarded insect1 and even to undertake the dissection of it4 ,but who would imagine that on this examination it should prove a perfect and surprising insect8 ,this is1 however1 a certain fact2 and thus in that infinite variety of works1 by means of which ,god is pleased to make ,himself known to us1 we ever meet with new matter of admiration and astonishment4 #8,this little creature being extracted from the shell that covered it1 looks like a young spider before it has left its egg4 ,on the fore part is the head 7,fig4 #dc;,d1 a7 and on its head are the eyes1 b3 under the eyes are placed its little legs elegantly coiled and folded1 c c2 but they appear much more distinctly on turning the insect on its back1 d d2 and in this situation also it best appears with what art these legs are laid up in the shell1 and all are covered with hair4 ,the colour of this little creature is1 as ,i have already observed1 a mean between that of vermilion and purple2 and this colour shows itself through the coat or shell1 which is transparent4 ,i cannot determine to what species of insects this is to be referred2 nor can ,i say to what size it grows1 or by what kind of creature it is thus deposited on the ,water ,scorpion in the form of an egg1 there to receive life and growth4 ,nevertheless1 ,i cannot but look on the discovery ,i have made as very interesting1 since it proves that there are in the nature of things eggs which acquire a sensible growth by an entraneous nourishment1 unless perhaps some naturalist should choose to consider this as a complete insect1 rather than as an egg2 nor shall ,i strenuously oppose his opinion1 seeing that1 in all cases1 the egg is in reality no other than the insect itself1 which remains in that state till it has acquired sufficient strength to break its prison1 and live without such a covering#ce4' ,having quoted ,swammerdam1 let us see what ,de ,geer has to say on the subject3-- #8,on the body and legs of many aquatic insects1 such as ,dytiscus and ,water ,scorpions1 may be frequently seen little oval1 seed-like bodies1 of a bright red colour1 firmly attached1 and1 as it were1 implanted in the skin1 by a little stalk4 ,i have had ,water ,scorpions with the upper surface so covered with these red bodies that there was scarcely a vacant space on the skin4 ,they are most frequently to be seen in the spring2 but the insects on which there was such a great number did not live long with me4 ,having crushed some of these seed-like bodies1 ,i found them filled with red liquid matter4 ,i am convinced1 by experiment1 that they are the eggs of ,water ,mites1 since there came out of them little red ,mites with round bodies and long legs1 which swam about with great swiftness4 #8,these red ,water ,mites1 then1 attach their eggs to the bodies and legs of larger aquatic insects1 and there they remain till the young are hatched4 ,and since we find eggs of many different sizes1 we may be sure that they grow and increase in size1 doubtless owing to a certain nutritive juice which passes from the body of the insect into the egg4 ,hence it is1 as ,i have seen myself1 that ,water ,scorpions loaded with these eggs become weak and feeble1 because they are obliged to furnish their hangers-on with nourishment from their own bodies4 ,moreover1 these eggs appear to cause the ,water ,scorpions some irritation or uneasiness1 since ,i have often seen them rub with their feet those parts of the body where the eggs were2 and perhaps they did this with the view of rubbing them off1 but they were too securely fastened#cf4' ,dugs watched the development of the common ,red ,water ,mite 7,fig4 #ei71 and tells us that towards the end of ,may the females deposit their eggs in the leaves of pondweed1 which they puncture with their beaks4 ,the larva 7,fig4 #fj71 red in colour1 with six legs1 is free-swimming1 and has a large beak1 which looks like a great head1 and terminates in a narrow mouth4 ,it is not known how long this larval stage continues2 but in the next stage 7,fig4 #fa7 the ,mite becomes parasitic on aquatic beetles and bugs1 fastening its beak into the body of its host1 from which it derives its nourishment4 ,the legs and palps are often retracted or absorbed1 so that it is not difficult to understand how it was ,swammerdam and ,de ,geer took these parasitic nymphs to be the eggs of the ,mite4 ,during their parasitic condition they increase considerably in size1 at last emerging as adult eight-legged free-swimming ,mites4 ,it was just before the emergence of the ,mite that ,swammerdam examined the parasitic nymph1 for he figures the #8insect1' which he extracted from the egg1 as having eight legs 7,fig4 #dc;,d74 ,illustration3 ,,fig4 #fj4--,larva of ,water ,mite4 ,illustration3 ,,fig4 #fa4--,nymph of ,water ,mite4 ,i once found a ,water ,mite in the body of a ,dytiscus#cg4 ,i was breaking up the beetle1 and had removed the elytra and the wings4 ,i only wanted the external skeleton2 so a slit was made between the plates of the dorsal and ventral surface1 and the intestines removed4 ,the ,mite was embedded in the fat-body4 ,i could find no mention in the literature of ,beetles or ,mites of any similar occurrence2 and should scarcely have mentioned it here1 had ,i not been unexpectedly confirmed by my friend ,mr4 ,g4 ,e4 ,mainland1 ,f4,r4,m4,s41 who once had a similar experience1 and who kindly allows me to quote from a letter he sent me on the subject3-- #8,i am sorry to say ,i can find no documentary evidence as to the ,arachnid ,i found embedded in the tissues of ,dytiscus1 but a good deal has come back to my recollection4 ,on removing the right elytron and slitting up the dorsal surface1 ,i found it in the tissue close up to the thorax4 ,i cannot recollect what ultimately became of it1 after ,i had shown it to friends at the ,hackney ,microscopical ,society4444 ,i know that ,i carefully measured the ,hydrachna 7which was abnormally large7 and its relative size to that of its host1 and made a comparison in a lecture 7to the ,senior ,band of ,hope at ,st4 ,michael's1 ,hackney7 of a man with a creature as large as a guinea-pig under his shoulder-blade4' ,the occurrence of the ,mite inside the ,beetle was1 of course1 quite exceptional4 ,it probably found its way in through one of the abdominal spiracles4 ,the ,beetle ,mite 7,gamasus coleoptratorum7 7,fig4 #fb7 is extremely common1 and is parasitic on the ,dung ,beetle and on the ,humble ,bee1 so that in order to examine the parasite we must capture the host4 ,there can be no difficulty about this1 for ,dung ,beetles and ,humble ,bees are plentiful enough4 ,this ,beetle ,mite1 apparently1 does not infest other species of beetles4 ,i have kept the ,devil's ,coach ,horse in a bottle with the common ,dung ,beetle for some months1 and though the latter swarmed with these parasites1 they never left their host for the other beetle4 ,even when removed by means of a small brush from one beetle to the other1 they left the ,devil's ,coach ,horse of their own accord1 and soon made their way back to the ,dung ,beetle4 ,illustration3 ,,fig4 #fb4--;,beetle ,mite4 ,these parasites1 with their host1 came into my possession in a strange way4 ,a friend1 who knew my hobbies1 told me that he had managed to procure for me some young beetles just born4 ,i ventured to suggest that beetles were not born as beetles1 but in quite a different shape4 ,my suggestion was received unsympathetically1 and ,i was told that ,i should alter my opinion when the creatures were sent me4 ,but ,i did not4 ,the box contained a ,dung ,beetle1 over which were swarming scores of these little ,mites1 and ,i had some difficulty in convincing the gentleman who sent them to me that these ,mites were not the young of the beetle4 ,we should compare this ,beetle ,mite with the ,water ,mite1 and notice the difference in the mouth parts and the legs1 which have a large pad between the claws4 ,we may find another ,beetle ,mite1 closely allied to this species1 on the ,devil's ,coach ,horse1 and some of its near relations4 ,this ,mite was also known to ,de ,geer#ch1 whose remarks upon it are worth quoting1 in a condensed form4 ,he found a beetle covered with these ,mites1 and on examining them with a hand lens saw that they were attached to their host by a long thread or stalk1 which came from the posterior end of the body4 ,several ,mites1 he tells us1 were joined together by one thread which fastened them all to the beetle2 and he came to the conclusion that the parasites were nourished at the expense of the beetle1 the thread serving to convey the juices of its body to them4 #8,it is very singular1' he says1 #8to see living insects planted on the body of larger insects1 from which they draw their subsistence by means of a thread or stalk4' ,and then he goes on to compare these #8vegetative ,mites1' as he calls them1 with the #8eggs' of the ,water ,mites1 which he found on ,dytiscus and the ,water ,scorpion4 ,the thread exists1 and the ,mites are attached by it to their host1 but they do not draw nourishment through it from the beetle1 for it is composed of their excrements4 ,the ,myriapods are worm-shaped creatures1 breathing by means of air-tubes1 and furnished with a number of limbs closely resembling each other4 ,there are two groups3 the ,centipedes and the ,millepedes4 ,the former have the body flattened1 with one pair of appendages to each segment1 the first pair being modified into piercing poison-organs1 and they feed on living prey4 ,the body of the ,millepedes is round1 with two pairs of appendages to each segment2 they have no poison-organs1 and their food consists chiefly1 if not entirely1 of vegetable matter4 ,there seems to be some doubt1 however1 as to whether ,julus1 one of the commonest ,millepedes1 does not occasionally indulge in animal food4 ,in ,nature ,notes 7,jan4 #ahif7 there was a review of the ,cambridge ,natural ,history 7vol4 v74 ,the reviewer1 in a brief summary of ,mr4 ,sinclair's part of the book 7the ,myriapods71 said1 after describing the ,centipedes3 #8,the millepedes1 on the contrary1 are sluggish vegetarians1 with hard1 cylindrical bodies1 c4' ,on this a correspondent wrote in the ,march number3 #8,some time ago my attention was attracted to a large earthworm1 writhing and twisting about on the garden path1 as though in pain1 or through having received some injury4 ,on examining it more closely to ascertain the cause of its unusual movements1 ,i found that a millepede had fastened itself to the side of the worm1 and appeared to be boring or eating its way into the body1 whilst the most violent efforts on the part of the worm were ineffectual in shaking off its antagonist4 ,if the millepede is a vegetarian1 what could be its object in attacking so harmless and defenceless a creature as the earthworm8 ,the above1 which ,i take to be a millepede1 is the black or dark-coloured creature 8with hard1 cylindrical body0 ordinarily found coiled up in a spiral under stones or rubbish4' ,the editor1 as a matter of course1 referred the matter to the writer of the review4 ,his reply was as follows3 #8,if there is no mistake about the identity of the aggressor in the account cited above1 the observation is one of considerable interest2 for1 so far as we are aware1 it is the only case on record of a millepede being guilty of such conduct4 ,but were it not for the positive statement that the species was the dark-coloured creature with a hard1 cylindrical body1 which is ordinarily found coiled up in a spiral under stones or rubbish--a description which exactly applies to the millepedes of the genus ,julus--we should have concluded without hesitation that the struggle in question was merely one of those that habitually takes place between the centipedes of the genera ,lithobius or ,geophilus and the earthworms upon which they feed4' ,both the ,centipedes and ,millepedes are shy1 light-shunning animals1 and if we turn over some stones in the garden or in a walk through the fields we shall probably find specimens enough to serve us in getting some idea of both groups4 ,the ,centipedes are sometimes called #8,hundred-legs1' but this implies the possession of many more legs than the creatures really have4 ,in ,norfolk and ,suffolk the people call them #8,forty-legs1' and this is much nearer the mark4 ,lithobius forficatus1 about an inch long and rufous brown in colour1 is extremely abundant under stones and the bark of trees1 and in cellars and outhouses4 ,these animals run with great rapidity when disturbed1 so that one needs to be on the alert to seize them when they are driven from the places in which they lurk4 ,the body has nine principal and six subsidiary or smaller rings1 and there are fifteen pairs of walking legs1 besides the first pair1 which are modified to serve as poison-organs4 ,de ,geer says that he never dared to pick up these ,centipedes with ungloved hands1 because he had seen a fly1 which had been bitten by one1 die on the spot1 #8which seems to be a sign that their bite is venomous4' ,he examined their modified legs with a good microscope1 but could not distinguish any opening4 ,there is1 however1 an opening1 as ,de ,geer suspected1 though he could not distinguish it2 it lies near the point1 and we may also trace the canal through the claw down to the poison-glands which lie1 one on each side1 at the base of the claws4 ,the mouth parts resemble those of insects1 and may be dissected out in the same way4 ,when this ,centipede walks1 says ,de ,geer1 it does not use the last four pairs of legs1 but drags them after it2 but when it walks backwards1 which it does as well as forwards1 it then makes use of these four pairs of legs in the same way as the others4 ,if we keep ,lithobius alive we shall see that it can walk backwards1 though it can scarcely be said to go as well one way as the other4 ,from the same old writer some useful hints as to the method of keeping these animals may be gathered4 ,those that he kept in a vessel without any moisture soon died1 and were quite dried up in twenty-four hours1 which will teach us to keep them in a vessel with damp earth1 shaded from light and heat4 ,dr4 ,sharp#ci gives some interesting details about the breeding habits of ,lithobius1 and describes1 for the first time1 the uses of the two hooks on the under surface of the body of the female4 ,he experimented with ,centipedes and ,millepedes4 ,keeping them in large shallow glass vessels1 the bottom of which was covered with a layer of earth1 he fed the specimens of ,lithobius on insects and worms1 and sometimes on raw chopped meat1 but they did not thrive on this as they did on prey which they could kill for themselves4 ,illustration3 ,,fig4 #fc4--;,a4 ,lithobius forficatus4 ,b4 ,mouth parts seen from below 7,after ,graber47 ,lithobius1 he tells us1 lays but few eggs compared with the number deposited by ,julus4 ,each egg1 as it leaves the oviduct1 is received by the hooks mentioned above1 and by means of them it is rolled on the soil till a covering of earth adheres to the viscous material with which the egg is coated4 ,the male considers the eggs special delicacies1 and devours them whenever he has the opportunity4 ,it is to prevent this that the female covers them with earth1 so that the male may not recognize them4 ,geophilus is a much longer animal than ,lithobius1 for its body may consist of from #hj to #ahj rings4 ,the species have no eyes4 ,several of them are common1 especially in the south of ,england1 and possess1 as do many genera of the same family1 the property of phosphorescence1 whence have arisen the stories of #8luminous earthworms' current from time to time4 ,geophilus crassipes is the form most frequently captured when displaying its light4 ,it is from one inch to two inches long1 of a reddish-orange colour1 and somewhat worm-like in shape4 ,mr4 ,pocock1 of the ,british ,museum 7,natural ,history71 says3 #8,the property of luminosity lies in an adhesive fluid secreted by glands which open upon the lower surface of the body1 and the power of discharging or retaining the fluid appears to be entirely under the centipede's control4 ,the phenomenon is observable during the autumn months1 from about the middle of ,september to the end of ,november1 and although its significance is not clearly understood1 it is generally believed to be connected with the pairing of the sexes#dj4' ,during a visit to the seaside it is well to look out for specimens of a marine ,centipede1 which is1 apparently1 not very common4 ,it is said to occur #8under stones and sea-weeds on the shore at or near ,plymouth'2 and in #ahie ,i had the good fortune to meet with one at ,bexhill4 ,this ,centipede does not live in the sea1 but will survive prolonged immersion in salt water4 ,it is far too valuable for us to pick to pieces1 so that1 if we should have the good fortune to meet with one1 we should carefully examine it1 making what notes are necessary1 and then pickle the specimen and send it to the ,british ,museum1 ,cromwell ,road1 ,s4,w4 ,the tube should be labelled with the place and date of capture1 and it should be stated on the label whether the animal was taken above or below high-water mark4 ,the ,common ,millepede--often miscalled the wireworm--is readily distinguished by the absence of poison-claws1 and its cylindrical worm-like appearance4 ,de ,geer1 who of course adopted the ,linnaean definition of #8,insects1' says of the ,millepedes of the genus ,julus1 to which our ,common ,millepede 7,julus terrestris7 belongs3 #8,they form1 as it were1 the last link of the chain which unites the class of ,insects to that of ,worms1 for the body is elongated and cylindrical2 and though they have a great number of feet1 these are so short1 that when these animals walk1 they seem rather to glide along after the fashion of legless worms#da4' ,illustration3 ,,fig4 #fd4--,the ,common ,millepede4 ,dr4 ,sharp says that these animals do very well in confinement1 and he found that sliced apples and grass formed the best food for them4 ,he watched the process of nest-making and egg-laying1 and these creatures are so abundant1 and the necessary appliances so simple1 that we may follow his example and see it for ourselves4 ,his arrangements were the same as for ,lithobius1 and he saw the female make a hollow sphere of a bit of earth1 stuck together by the secretion from the salivary glands1 and smooth on the inside4 ,a small hole was left on the top1 and through this she passed in from #fj to #ajj eggs1 closing the aperture with earth moistened with the salivary secretion4 ,the eggs were hatched in about twelve days4 ,the young of all the ,myriapods when they leave the egg have but three pairs of legs1 but the number of limbs and segments is increased at each successive moult4 ,having watched our ,millepedes in confinement1 it will be well to take a preserved specimen and examine it carefully with the pocket lens1 so as to compare it with the ,centipede2 then to compare both with the common earthworm1 and to note the points of likeness and of difference4 ,the dark spots on each segment in the illustration show the stigmata4 ,illustration3 ,,fig4 #fe4--,segments of ,millepede 7magnified74 ,,chapter ,v ,,crustaceans4--,,prawn1 ,,shrimp1 ,,mysis1 ,,crabs2 ,,amphipods2 ,,isopods ,the next group of ,arthropod animals with which we have to deal is that of the ,crustacea4 ,some or other of the members of this class are well known to everybody1 if only in the shape of toothsome food--the ,prawn1 the ,shrimp1 the ,lobster1 the ,crayfish1 and the ,crab4 ,the great characteristic of this class of the ,arthropod phylum is the so-called #8shell1' which differs greatly from true shell in being composed of chitine1 hardened with salts of lime4 ,most of the species live in the water and breathe by means of gills or through the skin4 ,in dealing with these creatures1 some long words must be employed1 if our present work on them is to be a stepping-stone to something more advanced4 ,the difficulty is more apparent than real1 and if boldly faced will soon be overcome4 ,our first division1 or sub-class1 of the ,crustacea is that of the ,malacostraca1 or animals with soft shells--a name originally adopted1 as ,mr4 ,stebbing tells us#db1 #8to distinguish such creatures as crabs and crawfish and prawns from such others as oysters and clams2 not because of the absolute1 but because of the comparative softness of their shells4' ,under this sub-class are grouped two ,orders--the ,stalked-eyed and the ,sessile-eyed ,crustaceans1 the technical names for which are the ,podophthalma and the ,edriophthalma4 ,to the ,stalked-eyed ,crustaceans belong the ,prawn1 the ,shrimp1 ,mysis1 or the ,opossum ,shrimp1 and the ,crabs1 to mention only those forms with which we are dealing here4 ,the reason for scientific and popular names will be evident if living or spirit specimens are examined1 for it will be seen that the eyes are elevated on stalks4 ,mr4 ,stebbing#dc relates an amusing story of a very intelligent student1 who1 on being told that the eyes 7of the shrimp7 were stalked1 candidly confessed to having always thought that this appearance was due to their having been forced out of the head by boiling4 ,the general shape of a ,prawn 7,palaemon serratus7 is fairly familiar to everybody4 ,the body is divided into two principal regions--the carapace1 or cephalothorax1 as it used to be called 7formed by the union of the head and thorax71 and the pleon1 or swimming part4 ,the carapace has a projecting beak or rostrum1 and is unsegmented2 the pleon is divided into segments1 and the whole may be represented thus3-- ---- -- -- -- -- -- -- 7 c #a #b #c #d #e #f t where the long stroke 7c7 stands for the carapace1 the shorter ones 7#a-f7 for the segments of the pleon1 and the 7 for the telson or tail4 ,the carapace consists of fourteen united segments1 and this will give twenty or twenty-one segments in all1 according as we reckon the telson an appendage of the sixth segment of the abdomen1 or as a distinct segment4 ,the carapace bears the eyes1 two pairs of antennae1 six pairs of mouth appendages1 and five pairs of walking legs or pereiopods1 normally with seven joints--in all1 fourteen pairs of appendages1 that is1 one pair for each of the fourteen segments of which the carapace is composed4 ,the segments #a-e of the pleon bear swimming feet1 or pleopods1 and the female uses these for retaining the eggs1 which she bears about with her4 ,in this fashion the #8hen' lobster carries her #8berries4' ,the ,prawn is a capital inmate of the aquarium1 and as it does well in confinement1 specimens should be kept in order to get a general acquaintance with their form and external anatomy1 and to watch their habits4 ,the ,common ,prawn will answer the purpose1 but still better is ,palaemonetes varians1 an exceedingly common species4 ,it has this advantage1 that it #8seems to be equally at home in salt water and fresh4' ,the only condition necessary is a good supply of food1 and this may be furnished by putting into the aquarium from time to time a quantity of water-fleas4 ,if these ,prawns are well fed they will shed their skins at frequent intervals1 and this operation will give us material for examination1 for the cast skin will serve our purpose almost as well as a spirit specimen4 ,some of these ,prawns are now living in one of my aquaria4 ,they were taken in a brackish dyke or cut near ,newhaven1 in ,sussex1 and in the mud which was brought back with them were a number of small bivalves of the genus ,sphaerium4 ,most people know ,mr4 ,kew's exceedingly interesting book1 ,the ,dispersal of ,shells#dd4 ,in it he relates some extraordinary instances of the way in which species of shells are carried short distances1 and may be carried from one district or country to another4 ,these ,prawns offered a good illustration of this1 and practically confirmed some of the statements in his book1 for on several occasions they were seen with the bivalve shells attached to their walking legs4 ,the molluscs lay half buried in the mud and vegetable dbris at the bottom of the tank1 and as the ,prawns walked about they sometimes trod between the open valves1 which1 as they closed1 fastened on to the intruding limb4 ,on one occasion the molluscs did not relax their grasp for days2 and had this incident occurred when the creatures were at liberty the molluscs might have been carried for a considerable distance4 ,if specimens of ,sphaerium are put into an aquarium containing ,prawns of this kind1 it is probable that before very long the crustaceans will have one or two attached to some of their limbs4 ,prawns are exceedingly beautiful1 and if we get hold of live specimens1 from salt water or fresh1 they should be put into an aquarium--the smaller1 in reason1 the better--so that their motions may be watched with the hand lens4 ,if much weed be put in1 the ,prawns will use their walking legs in preference1 while if there is little vegetation the powerful tail-fan will be employed for motion backwards1 while the five pairs of limbs on the abdomen enable their owners to move forwards through the water4 ,from ,fig4 #ff one may get a good notion of a ,prawn1 and of the points in which ,prawns1 in the zoological sense of the word1 differ from ,shrimps4 ,the head of the ,prawn is armed in front with a long blade-like beak1 studded along its upper and lower edges with a series of teeth like those of a saw1 and the second leg is chelate1 that is1 armed with pincers1 resembling1 in miniature1 that of a lobster or crab4 ,in the ,shrimp1 on the contrary1 there is scarcely a trace of the beak1 and the first leg is incompletely chelate1 or sub-chelate#de 7,fig4 #fg71 its last joint folding back upon the one that supports it1 just as the blade of a pocket-knife closes on its handle4 ,these two distinctions hold good between all ,prawns and all true ,shrimps4 ,illustration3 ,,fig4 #ff4--,prawn4 ,now let us go over our ,prawn--a spirit specimen--in detail4 ,the antennae may be separated1 and examined1 and the appendages of the inner pair distinguished1 for at first it may be thought that there are more than two pairs4 ,this1 however1 is not the case1 as should be ascertained by actual investigation4 ,a needle inserted at the base of the outer antennae will separate the first three segments1 bearing respectively the eyes1 and the first and second pairs of antennae4 ,the eye should be carefully looked at to make out that it is really compound4 ,then the joints of the antennae1 each with its circle of sense-hairs1 are to be noticed4 ,last of all1 the inner pair of antennae deserve attention1 for these carry in the basal joint an organ of hearing4 ,this joint is large and sac-like1 and contains an opening through which grains of sand are introduced by the animal itself4 ,the grains serve to transmit the vibrations of the water in the sac to the auditory hairs1 to each of which a branch is sent off from the auditory nerve4 ,if the joint is opened the sand will be found4 ,the first antennae of a lobster or crayfish may also be examined and compared4 ,the mouth organs1 of which there are six pairs1 will offer some difficulty1 and for this reason it may be well to pass them over in this case and to deal with these organs generally when treating of the ,crab4 ,beneath the outer foot-jaws are the first pair of walking feet1 which are used as cleansing organs4 ,gosse describes them as #8beset with hairs which stand out at right angles to the length of the limb1 radiating in all directions like the bristles of a bottle-brush4' ,if we watch our ,prawn in life1 we shall frequently see these limbs in active operation4 ,they are brought to bear on every part of the body within reach4 ,sowerby says#df3 #8,the prawn loves to be clean1 and he takes surprising pains to keep himself so4 ,drawing up his tail and abdomen1 he subjects their under surface to the most careful revision1 scrubbing and poking between the lappets of the shell and body1 diving into every crevice1 and with the pincer-hand picking out every speck too large to brush away4' ,the next pair of legs are also chelate2 but the three following pairs are armed with claws1 and it is upon the points of these that the animal walks on the bottom4 ,the pincers of the second pair of legs are used to pick up food and bring it up to the mouth organs1 where it is taken by the outer foot-jaws1 and passed into the mouth4 ,the swimming feet carry two branches1 finely fringed with hairs4 ,illustration3 ,,fig4 #fg4 ,first walking leg of ,shrimp 7enlarged74 ,if the carapace be removed the gills at the base of the walking feet will be exposed4 ,these consist of thin leaf-like plates attached to a central stalk1 and they are arated by water passing in behind and out in front4 ,after what has been said of the ,prawn1 little space need be devoted to the ,shrimp1 for it may be gone over in precisely the same way4 ,it will be sufficient to call attention to the difference in the antennae1 to the rudimentary rostrum or beak1 and to emphasize the distinction between the terminal joints of the first leg in the two creatures4 ,the leg shown in ,fig4 #fg corresponds to the limb used for cleansing by the ,prawn4 ,there is a great difference in their habits1 for ,shrimps burrow in the sand for concealment4 ,in doing this the swimming feet1 as well as the walking legs1 are brought into action1 and when the ,shrimp is settling down1 sand is swept over its back by the antennae1 to render the concealment complete4 ,in many of the rock-pools round the coast1 and also in brackish water1 ,mysis1 or the ,opossum ,shrimp1 may be met with4 ,it is not1 so far as my experience goes1 a good inmate of the aquarium1 but it is extremely interesting from the fact that1 unlike its higher relations1 the auditory apparatus is not situated in the antennae1 but in the plates of the telson 7,fig4 #fh;,e74 ,illustration3 ,,fig4 #fh4--,mysis1 or the ,opossum ,shrimp4 ,mysis is shrimp-like in general appearance but differs from ,shrimps in the structure of the legs1 in the absence of gills1 and in other particulars4 ,the telson consists of five pieces4 ,in each of the two inner and smaller pieces is an oval sac1 like that described in the basal joints of the first antennae of the ,prawn1 containing a single lens-shaped otolith1 consisting of chalky matter embedded in some organic substance4 #8,the vibration of the hairs in this sac is mechanical1 not depending on the life of the animal4 ,hensen took a ,mysis1 and fixed it in such a position that he could watch particular hairs with a microscope4 ,he then sounded a scale2 to most of the notes the hairs remained entirely passive1 but to some one it responded so violently and vibrated so rapidly as to become invisible4 ,when the note ceased the hair became quiet2 as soon as it was re-sounded1 the hair at once began to vibrate again4 ,other hairs1 in the same way1 responded to other notes4 ,the relation of the hairs to particular notes is probably determined by various conditions2 for instance1 by the length1 thickness1 c4#dg' ,we shall not be able at present to repeat ,hensen's experiment1 but we may break up the sac and extract the otolith1 which may be seen with the lenses at our command4 ,small specimens of the ,shore ,crab 7,carcinus maenas7 are fair game for us4 ,they will interest us while living in the aquarium1 and when dead we can put them into pickle1 and break them up at our leisure4 ,the broad shell of the ,crab--the crab-cart of children--corresponds to the carapace of the ,lobster1 the ,prawn1 and the ,shrimp1 and bears the same number of appendages--fourteen pairs4 ,to make out the pleon or swimming part1 it is only necessary to lay the crab on its back1 and1 with a needle1 or small knife1 turn back the flap--or #8apron1' as fishermen call it--which lies in a groove on the under surface4 ,here we shall find the pleopods1 or swimming feet1 though they are not really used for that purpose4 ,the eyes1 the two pairs of antennae1 and the five pairs of walking legs will offer no difficulty4 ,it is only necessary to remark that the terminal joints of the last pair of walking legs are flattened and fringed with hair1 showing some approach to the swimming crabs1 which use those organs to swim with4 ,now we may examine the mouth organs1 of which there are six pairs4 ,to do this1 the crab may be fixed1 with the back downwards1 or held lightly but firmly in the left hand4 ,the latter plan is perhaps the more convenient4 ,the index and middle fingers should support the carapace1 and the thumb should be placed on the pleon4 ,the outer pair of mouth organs are the third maxillipedes1 or jaw-feet4 ,these close the area of the mouth1 somewhat after the fashion of the double-doors of a cupboard1 though the hinging1 of course1 is different4 ,to open these jaw-feet1 a needle should be inserted at the top1 with a gentle pressure downwards and outwards4 ,the back of the crab is turned away from us1 so that the left jaw-foot should be pressed outwards to the right1 and the right jaw-foot to the left4 ,theoretically these limbs consist of the same number of joints as the pereiopods or walking legs2 and this is to be borne in mind1 even if we do not succeed--and we probably shall not--in tracing the full number of seven joints4 ,but we may notice and count the terminal joints1 and observe the fringing of the limb with hair4 ,a similar method of using the needle will enable us to raise the second and first pairs of maxillipedes1 which are of smaller size and softer structure4 ,having raised these organs1 it is well to replace them--to close the doors1 as it were--and then to raise them again1 to observe how they work4 ,they may then be detached and fastened to a small piece of card1 for comparison with similar organs in the lobster and the crayfish1 and with the mouth organs of insects4 ,beneath the maxillipedes are the second and first maxillae--thin1 leaf-like organs4 ,the first-named are furnished with spoon-like scoops1 which serve to carry out from the gill-chamber the water that has parted with its oxygen in arating the gills4 ,immediately below the maxillae lie the mandibles1 with hard1 cutting edges1 by means of which the food is broken up4 ,each carries a palp4 ,illustration3 ,,fig4 #fi4--,maxillipedes and ,maxilla 7b7 of ,shore ,crab4 7d7 ,first maxillipede4 7,after ,savigny47 ,these inner three pairs should also be detached1 and the whole of the mouth organs arranged on a card thus3-- ,,mandibles4 ,,first ,,maxillae4 ,,second ,,maxillae4 ,,first ,,maxillipedes4 ,,second ,,maxillipedes4 ,,third ,,maxillipedes4 ,the first attempt will certainly be unsuccessful2 and the first few attempts will probably be unsatisfactory2 but we shall gain knowledge with each successive trial4 ,and knowledge is worth the winning4 ,the stomach is interesting1 and the gastric mill may be easily examined4 ,when the mouth organs are removed1 there will be no difficulty in taking out the stomach4 ,this should be cut open with a needle1 and then we shall see the gastric teeth 7g g7 which grind up the food against the fixed calcareous plate 7b b74 ,the lower end of the stomach is set with fine hairs1 which prevent the passage of food into the intestines until it has been ground fine between these living millstones4 ,a similar arrangement is found in all the higher ,crustacea4 ,the time spent in comparing the gastric mill of the ,crab with the #8gizzard' of the ,cockroach will not be thrown away4 ,the ,broad-clawed ,porcelain ,crab 7,porcellana platycheles7 is also worth keeping1 for it is a droll little creature4 ,these crabs are generally to be found clinging to the under surface of stones or of ledges of rocks overhanging small pools4 ,the chief interest of these crabs1 for us1 lies in the exceedingly beautiful arrangement for procuring food with which the outer pair of foot-jaws is furnished4 ,illustration3 ,,fig4 #gj4--,stomach of ,crab laid open4 b b b1 fixed plate1 against which the gastric teeth g g are opposed2 b b1 gastric teeth enlarged4 #8,watching a ,broad-claw beneath a stone close to the side of my tank1 ,i noticed that his long antennae were continually flirted about2 these are doubtless sensitive organs of touch1 or some analogous sense1 which inform the animal of the presence1 and perhaps of the nature1 of objects within reach4 ,at the same time ,i remarked that the outer foot-jaws 7pedipalps7 were employed alternately in making casts1 being thrown out deliberately1 but without intermission1 and drawn in1 exactly in the manner of the fringed hand of a ,barnacle1 of which both the organ and the action strongly reminded me4 ,i looked at this more closely with the aid of a lens3 each foot-jaw formed a perfect spoon of hairs1 which at every cast expanded and partly closed4 ,that you may understand this better1 ,i must say that the foot-jaw resembles a sickle in form1 being composed of five joints1 of which the last four are curved like the blade of that implement4 ,each of these joints is set along its inner edge with a row of parallel bristles1 of which those of the last joint arch out in a semicircle1 continuing the curve of the limb2 the rest of the bristles are curved parallel or concentrical with these1 but diminish in length as they recede downwards4 ,it will be seen1 therefore1 that when the joints of the foot-jaw are thrown out1 approaching to a straight line1 the curved hairs are made to diverge2 but as the cast is made they resume their parallelism1 and sweep in1 as with a net1 the atoms of the embraced water#dh4' ,all this description may be verified from a spirit specimen1 if the foot-jaws be carefully removed4 ,and the examination with the lens will also show that these hairs are plumose1 that is1 set with smaller hair1 like the barbs of a feather4 ,at this point we may conveniently take leave of the ,stalk-eyed1 and pass on to the ,sessile-eyed1 ,crustacea4 ,leaving the ,cumacea out of the question1 we have two ,sub-orders from which to choose our subjects--the ,amphipoda and the ,isopoda--conveniently ,englished1 ,amphipods and ,isopods4 ,we learn from ,mr4 ,stebbing#di that #8the ,amphipoda1 which are common in fresh as well as in salt water1 were so named by the ,french naturalist ,latreille1 as having feet extending in all directions1 their limbs at the same time having much diversity of form1 in correspondence with diversity of function4 ,the ,isopoda1 or equalfooted animals1 besides being found both in fresh and salt water1 have more decidedly than the ,amphipoda extended their range to the dry land4 ,the name was invented by ,latreille in ignorance of the great number of species1 since investigated1 in which the feet are strikingly unlike and unequal4 ,nevertheless1 the name may stand1 just as a rose remains a rose even when it is not rose-coloured4' ,these last two sentences must be borne in mind1 for they throw great light on a subject that may give us some trouble--the question of priority in nomenclature4 ,the majority of the ,amphipods live in salt water1 but a few are found in ponds and streams1 and some dwell on the shore1 near1 but not in1 the sea4 ,the animals of this ,sub-order are distinctly segmented1 and three regions may be distinguished thus image1 where ,c stands for the ,cephalon1 or head1 ,per4 for the ,pereion1 or body1 and ,pl4 for the ,pleon 7literally1 the swimming part71 or tail4 ,on the head we shall find two pairs of antennae1 the eyes1 and the mouth appendages4 ,each segment of the pereion bears a pair of appendages2 the first two pairs are called respectively the first and second gnathopods 7or jaw-feet71 and the other five pairs pereiopods1 or walking feet4 ,the pleon carries three pairs of pleopods1 or swimming feet1 on the first three segments1 and each of the following three has a pair of uropods or tail appendages4 ,it is well to make out these parts in every specimen that comes in our way4 ,more is learnt by breaking up one specimen than by reading the clearest description so often that one knows it by heart4 ,illustration3 ,,fig4 #ga4--;,gammarus4 7,after ,sars47 ,we may begin with the ,fresh-water ,shrimp 7,gammarus pulex71 which may be taken abundantly in running water where there is plenty of vegetation4 ,willow-moss affords these ,crustaceans a favourite hiding-place4 ,it is an excellent plan to gather a quantity of weed and shake it over a newspaper or a piece of mackintosh4 ,the #8,shrimps'--which1 by the way1 are not really ,shrimps--will be dislodged from the weed1 and we shall see them wriggling along on their sides1 from which habit they and their near relatives are often called #8,scuds1' and #8,screws4' ,they are useful inmates of an aquarium1 because they feed on decaying animal matter1 and so keep the water pure and sweet4 ,opinions are divided as to whether these animals feed on water-plants2 it is probable that when their natural food fails them1 they take what comes in their way4 ,i have kept marine and fresh-water species of ,gammarus 7the genus to which the ,fresh-water ,shrimp belongs7 in tanks which contained no other animals1 but plenty of vegetation1 and both lived and did well for a considerable time4 ,they are by no means unwilling to make a meal off the dead body of one of their own species2 but it is exceedingly doubtful if they prey on each other1 as some old writers have asserted4 ,this notion probably arose from the fact that the male carries the female1 which is much smaller1 about with him1 during the period of courtship1 holding her tightly beneath his body by means of the fingers of its first two pairs of hands4 ,the habit is not confined to this genus1 nor even to this ,sub-order2 for some1 if not all1 the species of ,idotea carry on their courtship in similar fashion1 as does also the ,water ,woodlouse4 ,for the verification of statements such as these1 a small aquarium is necessary1 but the animals will not be under observation long before the observer will be convinced of their truth4 ,all species of ,gammarus1 whether living in the sea or fresh water1 may be readily distinguished by the rows of small spines on the three hinder segments of the pleon1 for this is one of the characteristic marks of the genus4 ,after we have kept specimens in the aquarium for a time1 so as to become familiar with their general appearance and habits1 we will put them to practical use by breaking them up4 ,our first task is to work over the animal as a whole1 and to make out the three regions--cephalon1 or head2 pereon1 or body2 and plon1 or swimming part1 or tail--into which it is divisible4 ,it will not be sufficient to do this once1 and then to imagine we have the whole matter fixed in our memory4 ,it should be repeated over and over again1 with every specimen that comes into our hands1 till we know these regions practically1 and the number and kind of appendages they carry4 ,and then the three rows of spines are to be looked for4 ,for all this the inch lens will be quite sufficient4 ,now let us separate the head4 ,when this is done1 and if we use the lens1 we shall at once be able to account for the name #8,sessile-eyed ,crustacea1' for the difference between the eyes of our specimen and those of a shrimp or a crab will be evident4 ,nor can there be any doubt that they are compound eyes1 though the outer integument is not divided into facets4 ,the antennae are next to be considered4 ,of these there are two pairs1 the superior1 or inner1 pair being the longer4 ,these antennae consist of three basal joints and a many-jointed flagellum1 or lash1 and on each of the inner pair is a secondary appendage1 arising from the distal 7or outer7 end of the third basal joint4 ,we may represent one of the superior antennae thus3 image4 ,the dashes represent the three basal joints1 the long row of dots the many-jointed flagellum1 and the slanting row of dots stands for the secondary appendage4 ,the sensory-hairs on the joints of the flagellum should be looked for1 and may be made out with the inch lens4 ,the same power will show the denticle1 or tooth-like projection at the base of the lower antennae4 ,next come the mouth parts4 ,as compared with ,crabs1 ,amphipods seem badly off in this respect2 for the second and third maxillipedes of the former become the first and second gnathopods of the latter1 so that instead of six pairs of mouth organs the ,amphipods have only four4 ,it is not an easy matter for a beginner to separate the mouth parts of an ,amphipod1 but the difficulty is not insuperable1 and will grow #8small by degrees and beautifully less' with practice4 ,we have to make out four pairs of organs arranged in the order given at the side of the page1 the mandibles being the innermost4 ,,mandibles4 ,,first ,,maxillae4 ,,second ,,maxillae4 ,,maxillipedes4 ,of course we must begin with the maxillipedes 7,fig4 #gb74 ,the specimen may be held between the finger and thumb1 and the parts picked out with a needle4 ,it is1 however1 better and easier to make the dissection under water4 ,then we can remove the second and first maxillae1 the latter easily recognizable by its palp or feeler4 ,last of all come the mandibles1 also bearing a palp4 ,we shall feel these under the needle1 because of their hardened cutting edges4 ,these are distinctly toothed4 ,when practice has made the separation of these parts fairly easy1 they should be compared with the mouth parts of other members of the group1 so as to utilize the knowledge we have gained4 ,illustration3 ,,fig4 #gb4--,maxillipedes of ,gammarus marinus 7in centre74 ,a4 ,first maxilla4 ,b4 ,second maxilla 7magnified74 ,next come the two pairs of gnathopods1 and in these we have to find seven joints--which may be denoted by the numbers #a1 #b1 #c1 #d1 #e1 #f1 #g2 #a being the basal joint1 or that nearest the body4 ,the sixth joint is often called the #8hand1' and the seventh1 the #8finger4' ,the joints vary greatly in different genera4 ,the walking legs are next to be examined1 and we may notice that the first and second pairs are turned forwards1 and the third1 fourth1 and fifth pairs backwards4 ,at the bases of these legs are the breathing apparatus1 and the females have leaf-like plates on the anterior four pairs1 forming a pouch in which the eggs are hatched1 and here she shelters her young1 and carries them about with her4 ,the following account of this habit is taken from ,bate and ,westwood's ,sessile-eyed ,crustaceae 7i4 pp4 #chj1 #cha71 and was furnished to the authors of that book by ,dr4 ,james ,salter3 #8,on catching a female with live larvae1 nothing is seen of the progeny till the parent has become at home in the aquarium1 when the little creatures leave her and swim about in her immediate neighbourhood4 ,the plan ,i have adopted to watch this curious habit of maternal protection1 has been to place a single individual in a bottle of sea water4 ,after a time1 and that soon1 the little crustacean seems at ease and swims slowly about1 when the young fry leave her and swarm around her in a perfect cloud2 they never leave her for more than half or three-quarters of an inch1 and as she slowly moves about they accompany her4 ,if now one taps the side of the bottle with one's finger-nail1 the swarm of larvae rush under their parent1 and in a second are out of sight4 ,the parent now becomes excited1 and swims about quickly1 as if trying to escape2 but by letting the bottle containing her rest quite still she soon gets composed1 when out come the young larvae again and swim about as before4 ,this may be repeated as often as the observer wishes1 and always with the same result4 ,i have only seen this in one species1 but it is quite a common species in ,poole ,harbour1 and ,i have watched the interesting habit many times4' ,the swimming legs are1 roughly speaking1 image-shaped--that is1 they consist of a stem1 carrying two many-jointed filaments1 fringed with fine plumose hairs4 ,a hair is said to be plumose when it bears smaller and finer hairs on each side4 #8,by folding the tail beneath the body1 and suddenly striking it out again1 those animals which exist in the water1 as well as those which live on the shore1 are enabled to dart or leap to a considerable distance#ej4' ,illustration3 ,,fig4 #gc4--,nest-building ,amphipod4 7,from life47 ,our hand lens may be well employed in watching some of the nest-building ,amphipods at work in the aquarium4 ,there can be no difficulty in keeping these creatures in captivity1 and under observation1 as they build their tubes and rear their families4 ,they are plentiful in every rock pool round the coast1 and it would be a hard matter to dip the net into any such pool without getting a few specimens4 ,they need absolutely no care4 ,the aquarium of the specimen figured was a four-ounce bottle1 tightly corked2 and in it was a spray of ,cladophora1 on which the animal fed1 and the growth of which broke up the carbon dioxide and set free good store of oxygen4 ,here it lived for some months1 and built more than one tube for itself against the side of the bottle4 ,it is easy enough through the pocket lens to watch the ,amphipod at work4 ,like other builders1 the first thing it does is to get its materials ready4 ,lying on its side1 with its back against the glass1 it will rake together with its antennae and jaw-feet a good store of vegetable dbris1 or if there be no supply of this1 will break off branches from the growing weed4 ,but gathering vegetable dbris1 or even filaments of living weed1 is very far from being tube-building4 ,something more is needed to bind the mass into a coherent structure4 ,this the animal itself supplies4 ,the bases of the first two pairs of walking feet are large1 and contain glands which secrete a glutinous cement1 that can be spread like mortar1 or spun out into threads4 ,an ,american observer devoted much time to the observation of these animals4 ,he says#ea3 #8,when captured and placed in a small zoophyte trough1 with small branching algae1 the individuals almost always proceeded at once to construct a tube1 and could very readily be observed under the microscope4444 ,the branches were not usually at once brought near enough together to serve as the framework of the tube1 but were gradually brought together by pulling them in and fastening them a little at a time until they were brought into the proper position1 where they were firmly held by means of a thick network of fine threads of cement spun from branch to branch4 ,after the tube had assumed very nearly its completed form1 it was still usually nothing but a transparent network of cement-threads woven among the branches of the weed4' ,then he describes the method in which the ,amphipod works up bits of weed and its own droppings into the framework of the tube4 ,in putting its foecal pellets to this use1 it reminds one of a species of ,melicerta 7,melicerta janus7#eb1 which employs the same material to coat its gelatinous sheath4 ,in breaking up weed and pellets with its foot-jaws and 7probably7 its mandibles1 the ,amphipod recalls the practice of some of the ,masking ,crabs1 which have been seen to apply to the mouth the material they were using to deck themselves4 ,dr4 ,aurivillius suggests that in the case of the ,crabs there may be an adhesive secretion from the mouth1 as there is possibly in the ,amphipods4 #8,the spinning was done wholly with the first and second pereiopods1 the tips of which were touched1 from point to point over the inside of the skeleton tube1 in a way that recalled strongly the movements of the hands in playing upon a piano4 ,the cement adhered at once to the points touched1 and spun out between them in uniform delicate threads4 ,the threads seemed to harden very quickly after they were spun1 and did not seem1 even from the first1 to adhere to the animal itself4 ,in one case1 in which the entire construction of the tube was watched1 the work was apparently very nearly or quite completed in little more than half an hour4' ,the species we are likely to meet with in rock-pools fashion their tubes in a similar way4 ,the only difference to be noted is that they employ less cement1 and a larger proportion of broken-down weed and other matters4 ,the ,sand-hopper 7,talitrus locusta7 and the ,shore-hopper 7,orchestia littorea7 are so exceedingly plentiful that it may be well to collect and preserve some during any visit to the seaside4 ,both are of fairly large size1 and present no great difficulty to us in making out their several parts4 ,let us take the ,sand-hopper first4 ,sand-hoppers swarm on most sandy shores1 where they perform the useful part of scavengers4 ,they are always found above high-water mark1 and do not enter the sea of their own accord4 ,in hunting for them it is a good plan to turn over decaying masses of sea-weed1 for under them the ,sand-hoppers are sure to swarm4 ,strange tales have been told of their voracity4 ,bate and ,westwood#ec record the story of a correspondent who says that at ,whitsand he #8saw 8not millions1 but cartloads10 of this species lying piled together along the margin of the sea4 ,they hopped and leaped about1 devouring each other1 as if for very wantonness4 ,a handkerchief1 which a lady let fall amongst them1 was soon reduced to a piece of open work by the minute jaws of these small creatures4' ,this statement has been copied into a good many books1 without criticism4 ,at last ,mr4 ,david ,robertson tried various experiments with a view to discover if these creatures would feed on each other1 or1 failing other food1 put up with cambric or muslin4 ,the specimens upon which he made his observations did neither the one nor the other4 ,mr4 ,robertson embodied the results of his experiments in a paper which he read before the ,natural ,history ,society of ,glasgow#ed4 ,and the story may be read in an abbreviated form in the ,rev4 ,t4 ,r4 ,r4 ,stebbing's ,naturalist of ,cumbrae1 p4 #cbi4 ,in ,gammarus we have a standard with which to compare our ,sand-hopper4 ,the first thing to notice is the difference in the antennae4 ,here the superior pair are very short1 and carry no secondary appendage1 and the lower pair have no denticle or tooth-like process4 ,there is also considerable difference in the gnathopods1 or jaw-feet1 the sixth joint of which1 in the ,sand-hopper1 does not form a #8hand4' ,the pleopods1 or swimming feet1 are small1 and are used for leaping4 ,we shall also find some difference in the details of the mouth parts1 especially in the toothing of the mandibles4 ,we now come naturally to the ,isopoda1 which are distinguished by the nearly uniform size of the seven segments which constitute the trunk1 and the seven pairs of limbs borne by these segments4 ,the head is distinct1 and the breathing apparatus is carried on the under side of the pleon--in these animals not the #8swimming' part--five pairs of plates lying one over another1 sometimes covered by a larger outer pair4 ,a normal ,isopod may be represented image3----1 where the small dash will stand for the cephalon1 or head2 the seven dots for the segments of the pereion1 and the long dash for the pleon4 ,the ,common ,asellus 7,asellus aquaticus7 of ponds and ditches is an excellent subject4 ,it lives well in confinement1 and if the conditions are fairly favourable1 will increase and multiply4 ,these animals will forage for themselves1 and pick up a comfortable living from the vegetable dbris that always accumulates at the bottom of an aquarium1 and they are not averse from an occasional meal of animal food4 ,illustration3 ,,fig4 #gd4 ,water ,woodlouse4 ,while our specimens of ,asellus are moving about in any convenient vessel1 we may verify with the hand lens what has been said about the general form4 ,then we may notice the antennae1 the inner pair being much the smaller4 ,there can be no difficulty in discriminating the head and the eyes2 the seven segments of the pereion1 each bearing a pair of limbs2 and the pleon with its two terminal appendages4 ,these last consist of a stalk bearing two longer filaments1 armed with spines1 and ending in a small pencil of hairs4 ,it is easy to see that the segments of the pleon have coalesced1 so as to form a continuous plate or shield on the upper surface4 ,if we now take our dissecting microscope and place an ,asellus in some water in an excavated #c in4 by #a in4 slip on the stage1 examination with an inch lens will show us a considerable amount of detail4 ,with the half-inch ,leitz lens 7see p4 #ah7 one may see quite clearly the beautifully annulated form of the flagella of the antennae1 the sensory hairs with which these organs are set1 and the circulation of the blood in the limbs and the antennae--the corpuscles moving in a continuous stream4 ,more than this3 we shall be able with the same power to distinguish tufts of ,vorticellids that settle on the ,asellus1 and the commensal rotifers that roam about on the body of their host1 generally on the limbs and under surface4 ,now we may turn the ,asellus on its back1 to examine the breathing apparatus more closely than we were able to do when the creature was moving about in the bottle4 ,it will be easy to make out the opercular plates--modified tail appendages--that open and shut to admit water to1 or allow it to flow out from1 the true breathing-plates which function as gills1 and correspond to the swimming feet of the ,amphipods4 ,in the female there is a pouch beneath the pereion1 in which the eggs are carried till they are hatched1 and which serves as a nursery and refuge for the young4 ,if a good number of these animals be collected they will probably breed1 and then there will be the opportunity of seeing for ourselves the young carried about in the incubatory pouch4 ,there are two other aquatic ,isopods which will make good subjects for us on account of their great abundance1 and the ease with which they may be kept in any improvised aquarium1 with a little weed4 ,they may both be taken in brackish water1 and will live and thrive in fresh water1 without any admixture of salt4 ,indeed1 both have lived for some months in a small bottle of ,new ,river water1 in which the only weed is some willow moss4 ,they feed on this and on the vegetable dbris that accumulates at the bottom of the bottle1 and both species have bred4 ,the first is ,idotea 7,i4 pelagica71 a long1 narrow creature1 with very short inner antennae4 ,the last four segments of the pleon form a plate on the upper surface2 and on the under surface the opercular plates may be opened like tiny folding-doors1 to show the breathing plates4 ,these vary greatly in colour4 ,of another species1 ,spence1 ,bate1 and ,westwood say3 #8,according to our experience the colour of the animal is dependent upon that of the weed on which it lives4 ,those that live on the black fucus are generally very dark purple1 while those that we find on the green algae are brightly verdant2 and it has always been our opinion that this change was due to the food#ee4' ,the other little creature is called ,sphaeroma--it has no ,english name--from the fact that it can roll itself into a ball4 ,it is not difficult to identify1 from the fact that all the segments of the pleon are joined into one plate1 the hinder margin of which is entire1 thus image4 ,the garden will afford us a hunting-ground for the last specimen of this group for which we have space--the ,woodlice4 ,enough has been said of the method of looking over and breaking-up ,isopods generally to render detailed description unnecessary4 ,the inner pair of antennae1 however1 are so small as to be readily overlooked3 indeed1 on first sight these creatures seem to have but a single pair4 ,some have1 and others have not1 the power of rolling themselves into a ball2 and1 concerning the former1 ,swammerdam tells the following story3-- #8,one of our maidservants had at one time found a great number of ,woodlice in the garden1 contracted into round balls 4441 and thinking she had found a kind of coral beads1 she began to put them one after another on a thread1 but it soon happened that these little creatures1 which roll themselves up in such a manner only for fear of harm1 and appear as if they were dead1 being obliged to throw off their mask1 resumed their motions4 ,on seeing which1 the maidservant was so greatly astonished1 that she threw away the ,woodlice and the thread1 and cried out1 and ran away#ef4' ,,chapter ,,vi ,,aquatic ,,insect ,,larvae ,in this chapter we shall deal with a few aquatic insect larvae4 ,of these1 some are aquatic also in the perfect condition1 while others emerge from the pupa stage as arial insects4 ,it requires no great amount of care to keep these creatures1 and some hints on this subject and on collecting are given in the first chapter4 ,the larva of ,dytiscus is abundant during the greater part of the year1 and is almost sure to be met with by the collector1 who will find it an extremely interesting object for examination and study4 ,no other creatures should be put in the same bottle with these larvae2 and if there are several of them in one bottle1 it is a good plan to put in plenty of pondweed1 which will often keep them from attacking each other4 ,when full grown1 the ,dytiscus larva may attain a length of two inches or rather more4 ,its colour is dingy brown1 and its aspect forbidding enough to justify the uncomplimentary names that have been bestowed upon it--,water-devil and ,water-tiger4 ,it certainly rivals the tiger in fierceness1 and its method of stealing up to its prey and attacking it from behind led ,swammerdam to call it the ,sicarius or ,assassin ,worm4 ,one must not imagine that ,swammerdam was ignorant of its nature2 #8worm' with him was a general term for any larval form4 ,indeed1 he says1 #8,it is extremely probable that some peculiar species of the ,water ,beetle proceeds from this worm1 when1 having remained in the water a sufficient time1 it betakes itself to the land to undergo its mutation2 but this is mere conjecture4' ,what was conjecture for him is fact for us4 ,now let us put our larva into a small tube1 and examine it more closely4 ,the head is large and joined to the first segment of the thorax by a distinct neck4 ,there are twelve small eyes1 six on each side1 a pair of antennae1 two pairs of palps1 and a large pair of sickle-shaped mandibles1 which ,swammerdam calls #8teeth1' and says that #8it is perhaps to contain the muscles such teeth require that ,nature has made the head so large4' ,behind the head come eleven segments1 of which the first and last are the longest4 ,they gradually increase in width till the sixth1 the rest again decreasing1 till the eleventh ends in a blunt point1 from which diverge two appendages1 thus image1 thickly fringed on both sides with hair1 as are the tenth and eleventh segments4 ,there are six legs1 one pair to each of the first three segments4 ,these also carry fringes of hair1 thus increasing their power as swimming organs2 and1 in addition1 they bear numerous spines1 and end in strong double claws1 which must be of service in climbing over aquatic vegetation1 and may assist in holding a struggling victim or in striking it down1 so as to bring it within reach of the mandibles4 ,spiracles will be found--seven on each side4 ,these do not1 however1 in the larval condition1 serve as breathing organs1 though they fulfil their proper office in the pupa4 ,the air-tubes of the larva open at the extremity of the last segment4 ,when the larva wants to breathe it comes to the surface without an effort1 for it is lighter than the water it displaces4 ,the tail rises above the surface1 and a fresh supply of air is taken in4 ,when the larva wishes to descend1 a stroke of the tail sends it downwards1 and as it reaches the bottom of the tube it will cling with its claws to any weed we may have put in with it1 or hold on with them to the glass itself4 ,the chief interest of this animal lies in its mandibles1 and the method in which they are employed4 ,it was formerly believed that the mouth of this larva was closed1 so that it could not take solid food1 and that it lived entirely on the juices of its prey1 which it sucked up through its hollow mandibles4 ,swammerdam says of this larva1 #8,when about to eat he seizes with the two teeth 7mandibles7 the little creatures that come in his way1 and pierces their body with the sharp crooked points4 ,the teeth being perforated from the points to the roots1 he in a surprising manner sucks through them into his mouth the blood of the unfortunate captive4 ,this may be easily seen1 especially when the blood of his prey is of a red colour1 as the teeth are transparent4' ,he then describes how he watched one of these larvae feed1 and saw the blood1 mixed with air-bubbles1 travel up the mandibles4 ,after this he tells us how1 if we have a ,dytiscus larva1 we may #8procure ourselves a very entertaining and surprising sight1 by throwing to it a small earthworm2 for let this last move1 twine1 and otherwise bestir itself ever so much1 the other keeps its hold1 and very calmly sucks the blood of its prisoner4' ,we may1 however1 go to work in another fashion4 ,we may dissect out the mandibles from a dead larva and pass a fine hair into the slit near the point1 and it will come out at the orifice near the base4 ,it is through this orifice that the nutritive juices of the prey are drawn into the true mouth4 ,this practical proof that the mandibles are pierced is by no means so difficult as one might suppose4 ,de ,geer#eg seems to have been the first to suggest that there must be some kind of true mouth1 and in support of his suggestion tells us that he saw this larva eating up the solid parts of a ,water ,woodlouse 7cloporte71 after having sucked up its juices4 ,more than this1 he places the mouth in what has proved to be the true position1 though he did not solve the mystery as to why it is kept so firmly closed4 ,this was done by ,mr4 ,burgess1 an ,american naturalist1 from whose paper#eh the following particulars are condensed3-- #8,authors have described this creature as mouthless2 and if we examine the slit where we should expect the mouth to be1 we find that this slit ends in a perfectly closed seam4 ,the methods of microscopical research were brought into play1 and a longitudinal section of the head cut and mounted4 ,this showed that the upper and lower lips were locked together by a peculiar joint--the upper coming over and locking into the under lip 7,fig4 #ge74' ,we may get some idea of this mouth-lock by placing the fingers of the right hand over those of the left1 and then bending them4 ,mr4 ,burgess concludes his paper thus3 #8,we find that the ,water-tiger1 far from being mouthless1 as ordinarily assumed1 has in fact a very wide mouth1 though its lips are closely locked together by a dove-tailed grooved joint developed for this purpose4 ,whether this joint can be unlocked by the animal itself is another question1 which ,i cannot answer1 though ,de ,geer's observation above quoted makes this probable4 ,it is1 at all events1 easy to open the mouth by manipulation with a pair of forceps4' ,illustration3 ,,fig4 #ge4--,mouth-lock4 m1 mouth #abe4 7,after ,burgess47 ,professor ,miall#ei has verified ,burgess's observations1 and carried them a step further4 ,he found by actual experiment that #8the mouth-lock acted automatically1 opening when the mandibles opened1 and closing when they closed4' ,both these authorities stand very high4 ,yet1 with all respect to them1 it will be well to test these statements before accepting them4 ,something of this mouth-lock may be seen in any well-prepared slide of a ,dytiscus larva4 ,if we hold the slide up to the light and examine with a power of #aj1 we shall see a dark line--in some cases two nearly parallel thinner lines--running from the base of one mandible to the base of the other4 ,the dark line is the closed mouth-lock4 ,the two nearly parallel thinner lines are the edges of the lips drawn asunder in preparing the specimen or by the pressure of the cover-glass4 ,if we get to see this much1 we shall have advanced one step4 ,illustration3 ,,fig4 #gf4--;,dytiscus ,larvae4 ,next we may verify ,professor ,miall's experiment1 though not quite in his way1 for such section-cutting as he speaks of is beyond our powers4 ,larvae as large as possible should be chosen1 and killed by dropping them into boiling water4 ,the mandibles of one should be allowed to remain closed1 and those of the other plugged open with pith or a small piece of wood--a bit of a match will serve4 ,by putting each in turn into an excavated slip with water1 carefully covering this with a plain slip1 and holding these slips together with an elastic band1 we may examine the larvae as we did the slide4 ,the result will be practically the same4 ,where the mandibles are closed1 we shall see the dark line2 and where they are open1 we shall see the two thinner ones nearly parallel4 ,one caution may be necessary4 ,the mandibles bear at the base a rounded process1 which fits into a chitinous cup4 ,it is not difficult to mistake this for the mouth-lock1 with which1 however1 it is not connected4 ,there is still one other method which we may adopt to see the mouth4 ,the head of one of these larvae may be cut off1 dropped into a strong solution of caustic potash1 where it should remain for a day or two4 ,after washing it well in water1 cut it in half lengthways1 and turning either half upon its side1 so as to expose the part cut1 examine with the pocket lens4 ,these experiments are by no means difficult4 ,but if carried out step by step1 it will be easy to understand how the larva can suck out the juices of its prey1 and how it can open its mouth to swallow some of the solid parts4 ,the larva does not readily change into a pupa in confinement4 ,if1 however1 we wish to rear a beetle1 the larva must be plentifully supplied with food1 and removed from a bottle to a flat dish1 where earth can be placed against the side so as to rise above the water-level4 ,fig4 #gg1 where a pupa is represented in a bank by the side of a pond1 will give us a hint how to go to work4 ,the time occupied in pupation will vary according to the temperature of the room--but is never less than a fortnight4 ,in the open it is probable that the winter is passed in the pupal condition1 the perfect insect emerging in the spring4 ,like ,land ,beetles1 it does not assume its dark hue for some days1 but its pale skin darkens by degrees4 ,illustration3 ,,fig4 #gg4--,pupa of ,dytiscus4 ,the larva of ,hydrophilus does not seem to be often taken in this country4 ,it would make a capital subject for investigation1 and the food-supply could be arranged easily enough4 ,the repetition of the experiences of ,lyonnet1 who reared these larvae from the egg1 would be of great interest4 ,he says that he took about thirty larvae from the brood1 and fed them with very small water-snails4 ,these they devoured in the same way as the larger larvae do4 ,having seized the snail with their mandibles1 they bent backwards1 and supporting it on their back1 which served them for a table1 eat it there1 without making any use of their legs to hold their prey4 ,when the supply of small snails ran short1 they did very well with large ones cut up into pieces1 and with tadpoles4 ,if1 however1 food was not supplied to them1 they fed on each other4 ,but1 except when pressed by hunger1 they lived together peaceably enough1 and seemed to take pleasure in each other's society#fj4 ,the larva of ,limnobia replicata1 a ,crane-fly allied to1 but smaller than1 the well-known ,daddy-longlegs1 is another excellent subject for investigation4 ,it is not very often taken2 perhaps because it is not often looked for4 ,but it is common enough1 for all that4 ,in general appearance these larvae resemble small caterpillars covered with spines4 ,some of these are simple and others forked1 not much unlike the letter image1 with a short stem1 and the arms slightly curved4 ,there are no feet1 and the last segment carries two pairs of hooks1 one large and the other small4 ,from their position they are called anal hooks4 ,the dykes of the ,sussex marshes are an excellent hunting-ground4 ,probably the channels of water-meadows1 or any other shallow standing water in which aquatic moss grows1 would serve the collector's purpose quite as well4 ,and such pieces of water abound all over the country4 ,for taking these larvae the ordinary net and bottle are of little use1 though a few may be captured by sweeping backwards and forwards among patches of aquatic moss4 ,there is1 however1 a far easier and surer method4 ,a good handful of the moss should be gathered1 and put into a shallow vessel half full of water--a developing-dish answers capitally--and then shaken to and fro or gently stirred with a small piece of stick4 ,the larvae will curl into a ring and fall to the bottom1 whence they may be picked up and dropped into a bottle or other receptacle to be taken home4 ,a fair quantity of moss should be gathered1 for this is their favourite food1 and all larvae are greedy feeders4 ,other water-plants1 however1 do not come amiss to them4 ,just before these lines were written ,i was examining a bottle in which some of these larvae were kept4 ,it contained a few sprays of willow-moss and some ivy-leaved duckweed1 which floated on the surface4 ,one larva on a spray of moss was reaching upward1 and it was distinctly seen to feed on the duckweed4 ,this must have been from choice1 for there was within reach plenty of what all observers consider to be its natural food4 ,this1 too1 might have been more easily obtained2 for1 to reach the duckweed1 the larva had to hold on to the moss by the anal hooks1 and extend its body in a fashion analogous to that of the caterpillar of a geometer moth1 which will hold on to a branch with its fore-legs and claspers and maintain the body at an angle of #de1 sometimes for hours together4 ,i have also seen them feed on hornwort4 ,the larva of this small ,crane-fly is not at all difficult to keep4 ,it is exceedingly hardy1 and will survive a great deal of rough treatment4 ,in ,november1 #ahie1 ,i sent three in a tube--securely packed1 as ,i thought--to a friend in ,yorkshire4 ,a few days afterwards ,i heard1 with regret1 #8that the bottle was broken in transit1 and that the larvae arrived dead4' ,three days later ,i was gratified by receiving a letter1 from which the following is quoted3 #8,the ,limnobia larvae have come to life again4 ,i put them into water as soon as they arrived1 and after lying motionless for many hours they have begun to creep about and feed4' ,this is excellent testimony to their powers of endurance1 but it is weak in comparison to that which ,de ,geer supplies#fa4 ,he was ,marshal of the ,court of ,sweden1 and one ,november1 before leaving his country house for his official duties at ,stockholm1 he put four of these larvae into a vessel of water1 and left them to take their chance4 ,the water froze into a solid mass4 ,when he returned in the following ,may he found about half the water thawed1 and two of the larvae dead4 ,the others1 though they had been enclosed in ice all the winter1 were lively and in good condition4 ,he put them into another vessel with fresh water and some aquatic moss1 and at once they began to move about and commenced to feed4 ,both pupated by the fifteenth of the month1 and the perfect fly emerged after six days in the pupal stage4 ,illustration3 ,,fig4 #gh4--,larva of ,limnobia replicata4 ,the following description of this larva is principally condensed from ,de ,geer1 whence the figures are also taken4 ,the body is long and cylindrical1 and divided into eleven segments1 of which the first and largest is sub-triangular4 ,the second and third segments are shorter than the rest4 ,the head 7t7 is very small and completely retractile within the first segment1 the anterior margin of which completely closes the orifice1 so that1 in this condition1 the creature appears to be headless4 ,the body is covered with spines1 some simple and others branched4 ,on the first three segments there are only simple spines2 but from the fourth to the tenth segment inclusive there are also on each segment two forked spines--that is1 fourteen in all4 ,on the last segment the spines are simple1 and here are also four chitinous hooks1 one pair much larger than the other4 ,these simple spines carry a white vessel1 which extends throughout their whole length2 but in the forked spines there are two such vessels placed side by side in the stem1 and diverging one to each branch4 ,he comes to the conclusion that these spines are probably the breathing apparatus of the larva1 for they are similar to those which he observed in an aquatic caterpillar4 ,walker#fb calls these spines #8long filamentous processes1 which appear to be internally supplied with air-tubes1' but he does not seem to have taken the trouble to break up a specimen1 or he would have been in no doubt as to their real nature4 ,this is shown by the fact that the larva never comes to the surface to take in a supply of air1 but contents itself with the oxygen dissolved in the water4 ,illustration3 ,,fig4 #gi4--;,forked spine of ,limnobia1 enlarged2 the dark lines show air-tubes4 ,the pupa is quite as remarkable as the larva1 though the breathing apparatus does not assume the form of spines1 but consists of two #8trumpets1' one on each side of the head1 as is the case with the pupae of gnats1 using that term in a wide sense4 ,the colour is a greenish-brown1 dotted with black4 ,the abdomen is capable of a good deal of motion from side to side2 and by this means the pupa can raise itself to the surface of the water to take in a supply of air4 ,de ,geer remarked that when the pupa rose for this purpose it lay with its body horizontal1 having the lips of the trumpets a little above the surface4 ,it appeared not to like being placed on its back1 because in that position the trumpets cannot be raised above the surface4 ,when he tried the experiment of putting the pupa back downwards1 it wriggled over by bending the abdomen4 ,illustration3 ,,fig4 #hj4--,pupa case of ,limnobia4 7,from a photograph taken at the ,yorkshire ,college1 ,leeds47 ,on the abdomen there are several chitinous hooks1 which serve in some sort as substitutes for limbs4 ,by their means the pupa can moor itself to the stems of aquatic plants2 and this is necessary1 since its specific gravity being less than that of the water it would be always at the surface1 if it had no such means of anchorage4 ,and of course1 at the top of the water1 it would be exposed to the danger of being snapped up by birds4 ,de ,geer's specimen passed six days in the pupal state1 and then emerged as a perfect ,crane-fly4 ,my specimens did not emerge till after ten and eleven days of pupahood1 which seems strange1 as they were plentifully supplied with food in their larval stage4 ,the fly is a little more than half an inch long1 and may be distinguished from the common ,daddy-longlegs by the character of the wings1 which are folded somewhat like those of a wasp1 but with this difference3 that the wings of this fly are folded outward1 while those of the wasp are folded inwards4 ,when the insect wishes to fly1 it opens the fold so that the whole wing presents a plane surface1 but the fold reappears directly the ,crane-fly ceases its flight 7,frontispiece74 ,illustration3 ,,fig4 #ha4--;,fore-wing of ,bee1 showing marginal fold 7 #g74 ,de ,geer's allusion to the wing of the wasp might have been extended to most of the ,hymenoptera1 as we may see by examining the fore and hind wings of a bee or a sawfly4 ,dr4 ,sharp#fc says1 #8,the wings of the ,hymenoptera are remarkable for the beautiful manner in which the hinder one is united to the anterior one1 so that the two act in flight as a single organ4 ,the hind wing is furnished with a series of hooks1 and the hind margin of the front wing is curled over so that the hooks catch on to it4 ,in some of the parasitic forms the wings 444 have no hooks4 ,the powers of flight1 in these cases1 are probably but small4' ,if we were taking our subjects in consecutive order1 the larva of ,ptychoptera would properly come here1 as being that of a ,crane-fly4 ,but since it will be convenient to examine another larva which resemble ,limnobia in its breathing apparatus1 we will take next the larva of ,paraponyx stratiotata1 one of the ,china ,marks1 for it is extremely interesting and by no means hard to come by4 ,the ,china ,marks are small moths1 with white wings bearing dark markings1 which have been supposed to resemble ,chinese characters4 ,their larvae are aquatic in varying degree--that is1 some breathe air in the usual way1 by means of spiracles2 while others1 by means of gills1 breathe the oxygen dissolved in the water4 ,many collectors have1 no doubt1 taken these larvae1 and cast them away in the belief that they were caddis-worms4 ,such was the experience of the ,rev4 ,gregory ,bateman1 the author of ,fresh-water ,aquaria1 who says 7p4 #bei73 #8,while hunting for fresh-water animals1 one not seldom comes across an insect wrapped up in two or more green leaves1 or pieces of leaves1 of some aquatic plant4 ,the leaves and the animal have somewhat the appearance of a caddis-worm in its case2 in fact1 for a time1 before ,i knew what it was1 ,i mistook it 7and ,i daresay others have done so also7 for a caddis-worm4' ,the cases are usually1 but not invariably1 made from the food-plant of the insect4 ,mr4 ,bateman has noted that these larvae #8do not always confine themselves to the same weed1 either for food or for building material4' ,this has also been my experience4 ,a larva of the ,brown ,china ,mark1 recently taken on the ,norfolk ,broads--an excellent collecting ground for aquatic larvae--was put into a tube4 ,the case had been damaged1 and the only vegetation in the tube was a spray of bladderwort4 ,on examining the tube1 after some days1 ,i failed to find the larva4 ,the reason was evident on removing the cork1 a small part of which had been gnawed away to procure material for the repair of the larval case1 which was affixed to the under side4 ,the larva was dead and too much decayed to be put into pickle1 a circumstance ,i much regret1 as ,i should like to have preserved the larva in such a strange dwelling4 ,as it is1 ,i have only been able to keep the house without its tenant4 ,pondweed is the usual home of the larva of the ,brown ,china ,mark1 and from the leaves of this plant the first larval case is generally fashioned4 ,this was the species upon which ,raumur made his interesting observations1 most of which have been confirmed by succeeding observers4 ,in well-grown larvae the contrivance by which the animal is protected from contact with the water in which it lives should be noted1 as it may be easily1 with the hand lens4 ,the skin is thickly set with tiny protuberances between which the water cannot penetrate1 the surface film stretching from tip to tip of these prominences1 just as it does over the hairs that cover the body of a water-spider4 ,de ,geer#fd describes an aquatic larva of one of the ,china ,marks 7,paraponyx stratiotata71 which has its breathing apparatus fashioned on a similar plan to that of ,limnobia1 though there is some difference in the details4 ,he found his specimens on the leaves of the ,water ,soldier1 and his interesting account recalls the fact to memory that this remarkable plant was at one time called the ,marsh ,aloe--an exceedingly appropriate name4 ,he describes the filaments on the body of the larva1 and concluded that they were probably breathing-organs1 because of the dark-coloured vessels within them4 ,these he traced1 as we will presently do1 to their union in the stem of the gill1 and thence to the air-vessels running down each side of the body of the larva4 ,he fed them on leaves of the ,water ,soldier1 and kept them through the winter4 ,in the following ,june he found them preparing to undergo their transformation into the pupal stage1 and at the end of the month the moths came out4 ,he was gratified by seeing the congress of these insects4 ,the females deposited their eggs on the floating vegetation and on the sides of his aquarium1 a little below the surface of the water1 and in about eight days the young larvae were seen4 ,illustration3 ,,fig4 #hb4--,larva of ,paraponyx stratiotata 7enlarged74 ,these larvae must be very abundant1 though they do not seem to be often taken by collectors4 ,in describing an allied 7,american7 species1 which is found on ,vallisneria and pondweed1 ,mr4 ,hart says#fe1 #8,they feed at first exposed on the leaf1 but later two or even three leaves are loosely webbed together1 face to face1 by each larva1 between which it remains concealed while feeding4 ,they are1 therefore1 hard to discover unless their hiding-places are broken up by seining1 or the like1 when the larvae may be seen swimming about4' ,this is1 no doubt1 the reason why these larvae are not more often taken4 ,anything like a seine net is of course out of the question for us2 but masses of vegetation may be readily broken up by vigorously working the bottle and net backwards and forwards amongst them4 ,specimens ,i have seen were taken among duckweed2 and ,mr4 ,hart mentions one instance of part of the larval case being constructed of ivy-leaved duckweed1 #8which was abundant there at that time4' ,now let us bring our lens to bear1 so that we may make out the external structure1 and recognize the similarity of the breathing-organs of this ,moth-larva to those of the ,crane-fly larva already treated of 7p4 #afh74 ,in order to make out the scheme of the gills1 which is somewhat complicated1 one should first of all distinguish the spiracles1 remembering that they are not functional4 ,and it is best to begin with those on the middle segments of the body4 ,they may be detected as little dark spots1 sometimes enclosed in a ring4 ,the head1 the first segment of the thorax1 and the last segment of the body1 bear no gills2 the second segment of the thorax has but two pairs on each side2 and there is but a single gill on each side of the ninth segment of the body4 ,on the other 7nine7 body-segments there are the full number of five gills on each side1 arranged two above1 and three below the spiracle4 ,the upper pair are called supra-stigmals1 or gills which lie above the spiracles2 the lower pair are called infra-stigmals1 or gills which lie below the spiracles2 and the single one1 the lowest1 is known as the pedal or foot gill4 ,these technicalities need not give us any trouble here1 in our examination of the larva2 nor do they present any real difficulty4 ,but it is worth while to master the arrangement as soon as we get hold of one of these larvae1 and then we shall be able to take up and understand technical descriptions of this aquatic caterpillar and its allies1 in so far1 at least1 as they refer to the breathing apparatus4 ,the gills differ in their character3 some few are simple1 while most of them are more or less branched4 ,in ,limnobia the branching of the gills is into a simple fork2 in ,paraponyx this kind of division also occurs1 and in others most of the gill branches are also given off from the main stem below one of the branches of the fork4 ,in ,fig4 #hd we have a representation of one of these branched gills4 ,it will not be difficult for us to make out the details as there shown4 ,but the vessels that run down into the filaments1 constituting them breathing-organs1 are smaller than those of ,limnobia1 and will consequently require a little more care and patience before we can distinguish them4 ,illustration3 --------------- ,,gill ,,gill ,,spiracle ,,gill ,,gill ,,gill --------------- ,,fig4 #hc4--;,diagram of segment of ,paraponyx1 showing arrangements of tracheal gills4 ,illustration3 ,,fig4 #hd4--;,gill of ,paraponyx larva4 a1 b1 stem2 c1 d1 e1 f1 branches2 g1 attachment of the air-vessel of the gill to the main tracheae of the body4 7,after ,de ,geer47 ,one would think that1 with such an array of gills1 this larva ought to be in good case for its air-supply4 ,it may1 perhaps1 be doubted whether this is so4 ,at any rate1 the creature adopts the same plan as the larva of ,chironomus1 which has no gills at all1 for driving away from its case water that has parted with its oxygen4 ,water charged with oxygen pours into the case1 and so the air-supply is renewed4 ,this plan is nothing more than keeping the fore-part of the body in undulating motion1 the tail in both the larvae serving as a point of attachment4 ,one or two that ,i have kept made their cases against the side of the bottle1 and so afforded an excellent opportunity of seeing them in this motion4 ,the ,tanypus larva does the same thing4 ,against the side of one of my small aquaria a ,tanypus larva and a ,chironomus larva have both made tubes2 and as ,i look up from writing these lines ,i can see them both hard at this work4 ,the larva of the ,alder-fly 7,sialis lutarius7 is also furnished with tracheal gills1 seven on each side4 ,so little is known of the life-histories of common insects that it may be profitable to introduce the account of an observer who watched the deposition of the eggs and the emergence of the young larvae3 #8,on ,april #be ,i found1 on the rushes round the margin of a small pond1 a great many patches of eggs1 and shortly after observed many of the ,sialis lutarius depositing them4 #8,they form large patches of from two to three inches in length1 generally encircling the whole rush near the top1 but sometimes deposited on one side only1 and extended to about a line in breadth4 #8,i counted #ajj in a square line1 so that each batch may be fairly considered to contain from #b1jjj to #c1jjj eggs2 the greater portion of which must consequently perish either in the egg or larva state2 as1 common as the insect is1 and widely distributed throughout the country1 we should be perfectly overwhelmed with the swarms of the perfect insect if such were permitted1 when it is considered that round this one small pond there could not have been less than #ajj patches of them4 #8,the eggs are of a very singular form1 and placed in a slanting position4 #8,the females1 while depositing them1 appeared perfectly motionless on the rush1 and varied considerably in size1 being from five lines to nearly double that in length4 ,some parts of the patches of eggs are of a much lighter colour than the rest4 #8,on ,may #c ,i found many of the eggs hatching1 the little larvae tumbling about in great numbers1 with their bodies erected like the larvae of the ,staphylinidae4 #8,on putting them into water they swam about with the greatest activity1 wriggling and undulating their bodies about much like a serpent or the tadpoles1 and working their legs at the same time#ff4' ,the author draws attention to the disproportionately large head of the larvae1 which1 however1 he did not describe1 as he had #8brought some of them alive1 and some eggs for exhibition4' ,sialis larvae occur in most ponds with muddy bottoms4 ,they may be taken by scooping up some of the mud in a long-handled spoon--a most useful instrument for the collector--and washing it1 or by throwing in the drag1 and bringing to land a mass of water-weed1 roots and all4 ,a few may generally be detected near the roots4 ,they may be picked up with a small pair of forceps1 or with a brush1 and dropped into a bottle2 or1 better still1 into separate tubes2 for they are fierce and voracious1 and1 failing other food1 by no means indisposed to prey on each other4 ,their general appearance1 and especially their powerful mandibles1 give them some resemblance to the larvae of a water beetle1 for which a celebrated naturalist not unnaturally took them1 when he began to study them4 ,and this would seem to be the opinion of some mounters1 for ,i have a slide of the mouth parts of this larvae1 labelled #8,mouth parts of the larvae of a water beetle4' ,it was not till ,i had broken up a good many ,sialis larvae that ,i found out what the slide really was4 ,these larvae may be kept alive in small bottles of water1 if they are supplied with food4 ,they will eat ,chironomus larvae and those of ,tanypus4 ,professor ,miall has found that they will eat caddis-worms and ,may-fly larvae4 ,probably1 no small aquatic creatures that they can overcome are safe from them4 ,a larva that is full-fed1 and ready to change to become a pupa1 will measure about an inch in length or a little more 7,fig4 #he74 ,the general colour is brownish1 with dark markings4 ,the legs are powerful1 and our lens will show us that they end in two strong curved claws4 ,from each of the first seven segments of the abdomen are given off a pair of jointed tracheal gills or breathing-organs1 which are directed upwards and backwards when the larva is at rest--a rare occurrence--but which wave to and fro in the water when the creature is swimming4 ,from this fact has arisen the statement found in most books that the larva uses these gills not only for respiration1 but for locomotion4 ,professor ,miall has come to a contrary conclusion1 and1 as he has kindly informed me1 is confirmed in his opinion by the weakness of the muscles4 ,illustration3 ,,fig4 #he4--,larva of ,sialis 7enlarged74 ,it will be well to make repeated observations till we are satisfied on the subject4 ,when these larvae are kept1 the conditions necessary to provide them with food and to keep the water arated by means of growing vegetation are unfavourable to close observation4 ,it will1 therefore1 be necessary to remove one or more of these larvae to a bottle in which there is nothing but pure water4 ,the work is now rendered much easier4 ,there is nothing to obstruct4 ,as soon as the larvae reach the bottom they will walk round and round1 giving us a good opportunity of watching them4 ,in swimming--which may be backwards as well as forwards--the abdomen is waved from side to side4 ,to see the backward motion one need only put a dipping-tube or a pencil1 or the like1 in front of the larva1 so as to bar its progress4 ,the creature will retreat a step or two1 and then1 with a flourish of the abdomen1 dart back through the water4 ,the larva will sometimes wave the abdomen up and down1 just as one may see a ,chironomus larva do when it has affixed its dwelling to the side of the glass1 and this motion probably assists the process of respiration4 ,when the larvae have been watched under the conditions above described1 ,i have never been able to detect independent motion of the gills4 ,but it is better that every one should observe for himself1 and draw his own conclusions from what he sees4 ,now let us examine a specimen more closely with the lens1 or under the dissecting microscope4 ,the mouth parts may be broken up separately1 or a little careful manipulation will enable us to see the chief features without injuring the specimen4 ,the head is strong and massive1 and the group of ocelli1 or simple eyes1 may be clearly made out4 ,the antennae bear a small pencil of hairs1 no doubt sensory in function1 at the extremity1 but careful management of the light will be required to distinguish them4 ,the mandibles are extremely business-like instruments1 and each bears two strong teeth on the inner side4 ,next come the maxillae1 with their palps1 each of which has an appendage1 while each maxilla carries three strong spines4 ,the labium1 with its palps1 and the mentum1 with its saw-like notchings1 may be plainly seen4 ,the three segments of the thorax offer no difficulty4 ,the legs are worth more than a cursory examination from their apparatus of spines and double fringe of hairs4 ,nine body-segments succeed to the thorax1 and behind these is a long tail-like organ1 which some authors consider represents a tenth segment4 ,illustration3 h t #a #b #c #d #e #f #g #h #i tail -- ----- -- -- -- -- -- -- -- -- -- ------ ,,fig4 #hf4--;,diagram of ,sialis larva1 showing arrangement of gills 7represented by vertical lines74 h1 head2 t1 thorax2 #a-i1 segments of abdomen4 ,the gills are seven on each side1 and are given off from the spaces in front of the first seven segments of the abdomen4 ,each gill is five-jointed--an unusual arrangement1 for the gills of the larvae of ,limnobia and ,gyrinus are without joints4 ,with the half-inch ,leitz the branching tracheal tube in the gill may be seen1 as well as the double fringe of hairs and the long hairs at the extremity4 ,the tail-like organ1 though without joints1 bears a close resemblance to the gills4 ,it has two tracheal tubes running through it1 and it is fringed on both sides with hair4 ,indeed1 ,professor ,miall1 ,f4,r4,s41 compares it to #8two ordinary tracheal gills completely fused together4' ,the first glance will convince the observer that the comparison is just4 ,illustration3 ,,fig4 #hg4--,pupa of ,sialis4 ,the pupa 7,fig4 #hg7 need not detain us1 for the larva undergoes its transformation in the ground1 not in the water1 where it could be watched4 ,but it is interesting to notice that the legs and wings are enclosed in separate cases1 and that the segments of the abdomen bear spines4 ,these spines are extremely serviceable to the pupa when making its way out of its cell to emerge as a perfect insect1 which is well known1 especially to fishermen1 as the ,alder-fly4 ,it may be found near streams1 and rarely uses its wings4 ,ptychoptera paludosa is a small ,crane-fly1 with an aquatic larva which will repay observation4 ,it is one of the group generally called #8rat-tailed maggots1' from the peculiar character of the breathing apparatus1 which consists of a retractile tube at the end of the abdomen4 ,it is1 ,i believe1 better known to some dealers than the larva of the ,drone-fly1 the rat-tailed maggot of ,raumur4 ,a few months ago ,i wanted some ,drone-fly larvae1 and asked a dealer to supply me4 ,when the larvae arrived and were turned out for examination1 they proved to be ,ptychoptera larvae--which ,i did not want4 ,i naturally wrote to point out the mistake2 and was told1 in reply1 that the larvae sent were the only #8rat-tails' known to my correspondent4 ,this larva is a mud-dweller1 and is best captured by scooping up surface mud near the banks of pools and ditches1 just where the water shallows on to the shore4 ,this should be washed in a small dish or saucer1 so as to carry away the mud and leave the larvae wriggling on the bottom4 ,they may be picked up with a brush and dropped into a bottle for transport home4 ,there is not the slightest difficulty about keeping them for observation4 ,a bottle of the capacity of six or eight fluid ounces will make a good aquarium for a dozen or even twenty4 ,the bottom should be covered to the depth of about an inch with mud fairly rich in organic matter4 ,my own plan has been to use the accumulation from the bottom of a large aquarium4 ,in this the larvae will bury the body1 and feed1 the tail protruding and thrust up to the surface of the water1 of which there should be about two inches above the mud4 ,this is a liberal allowance of space4 ,a couple of these larvae lived with me for some months in a glass capsule two inches in diameter and three-quarters of an inch in height4 ,the mud at the bottom and the water covering it together measured about half an inch4 ,both pupated1 and in due time from the pupa cases a perfect insect came out4 ,but that larvae may pupate1 they require to be well fed4 ,how shall we know when the bulk of the nourishment has been extracted from the mud8 ,from the castings of the larvae2 and these1 though of a different shape1 are as easy to be distinguished as the castings of the earthworm in the garden or those of the lobworm on the seashore4 ,all the mud that passes through the bodies of the larvae is discharged in the form of tiny hard1 cylindrical pellets2 and when the mass consists of these pellets it should be changed1 or the larvae will go short of food4 ,they will1 however1 support long fasts4 ,from ,fig4 #hh we may get a good idea of the appearance of the larvae when kept in confinement4 ,the figures are rather less than natural size1 and all the attitudes were sketched from life4 ,one is seen extended on the bottom2 two are partially buried in the mud1 with the breathing-tube protruding4 ,the larva on the mud1 and bent into curves1 is just about to rise to the surface2 others are shown in the act of rising1 while one has its breathing-tube raised above the surface1 and another is attached by the breathing-tube to the side of the glass vessel4 ,the larva with the star-like process at the end of the tail is that of ,odontomyia1 a large bee-like fly4 ,illustration3 ,,fig4 #hh4--,larvae of ,ptychoptera paludosa 7from life74 ,a larva of good size1 like that of ,ptychoptera1 is especially easy to examine2 and by reason of its transparency the tracheal tubes may be clearly traced4 ,the under surface of the larva should be first looked at1 and its adaptation for existence in the mud of a pond-bottom will be evident4 ,the creature is legless1 but possesses three pairs of false legs armed with dark-coloured hooks1 and each body-segment bears a circle of stiff hairs1 which enable the larva to travel through the mud1 in the same way that the earthworm moves through the soil4 ,moreover1 the segments between these circles are pretty thickly set with hairs4 ,the tracheal tubes run down on each side of the body1 not in a direct line1 for there is a most ingenious arrangement by which contraction and expansion of the larva1 and the protrusion and retraction of the tail1 are provided for4 ,one can easily discern that in most of the segments the tubes are large1 and that these large portions are connected by smaller tubes1 whence others are given off into the body4 ,these connecting-tubes are loop-like when the larva is of the normal length1 but are straightened out1 thus adding to their length1 when the larva is extended4 ,the opening and closing of these loops may be observed at leisure if a larva be put in a long excavated slip1 with some water1 and then covered with a plain glass slip4 ,the two slips1 fastened together with small elastic bands1 should then be laid on the stage of the dissecting microscope for examination2 or they may be held in the hands1 and the movements of the larva watched with the hand lens4 ,in the posterior segments of the body the tracheal tubes run side by side1 while in the tail itself they are1 so to speak1 intertwined4 ,when the tip of the tail pierces the surface-film a fresh supply of air is taken in4 ,at the base of the extensile portion are two processes which diverge1 one on each side1 at an angle of #de degrees4 ,these1 according to a ,german observer1 are tracheal gills1 and they are absorbed just before the larva enters the pupal condition4 ,raumur found these larvae plentifully in the ,bois de ,boulogne1 and gives a figure#fg4 ,he was not1 however1 successful in rearing the fly4 ,lyonnet not only took the larvae and kept them in an aquarium1 but watched their change into the pupal condition1 and saw them emerge as perfect insects4 ,an abstract of this description will probably be of interest4 ,illustration3 ,,fig4 #hi4--;,a4 ,ptychoptera larva 7enlarged74 ,b4 ,tail1 showing air-vessels 7still more enlarged74 7,after ,lyonnet47 ,he tells us that the larvae showed signs of changing into pupae in ,june4 ,the change was made without the larvae leaving the water1 and they underwent all their transformations in less than a fortnight4 ,at the approach of the change the larvae became whiter in colour1 but less transparent4 ,then they cast their skin1 leaving therein the air-vessels1 or rather their external covering4 ,after this last moult was over1 he was surprised to find that the tube which formed the tail of the larva1 and by which it took in a supply of air1 though it serves the same purpose in the pupa1 is attached to the thorax1 near the top of the head#fh4 ,lyonnet appears to have overlooked the fact that there was a second and shorter tube given off from the thorax1 which most observers consider to be functionless 7,fig4 #ij74 ,illustration3 ,,fig4 #ij4--,pupa of ,ptychoptera4 7,after ,lyonnet47 ,strange as is the larva1 the pupa is stranger still1 and seems even better adapted for existence in the mud4 ,the hinder part of each segment of the abdomen is thickened and studded with chitinous projections4 ,this thickening is more marked1 and of greater extent in each succeeding segment1 reaching its greatest development in the last segment1 which is armed with hooks4 ,the body part of each segment bears rows of smaller spines1 so that this pupa should have little or no difficulty in moving through pretty thick mud4 ,several of these ,crane-flies have passed through all their stages with me1 and in nearly every case the transformation from pupa to perfect insect was made in water--in a tube three inches long1 with a diameter of about an inch4 ,the larvae were taken about the middle of ,september4 ,my notes show that the first pupated on ,november #ag1 and the first fly came out on ,november #be4 ,the long breathing-tube of the pupa was several times purposely displaced from its position on the surface4 ,the creature was evidently incommoded1 and twisted itself into strong curves2 the head was thrown from side to side till part of the breathing-tube was raised above the surface and adhered to the side of the glass tube4 ,nor did the efforts cease till a considerable portion of the tube was in free communication with the air4 ,this would seem to show that the air-supply is taken through the bladders which appear at irregular intervals in the breathing-tube1 and not at the tip1 where the keenest observers have failed to find an opening4 ,,index ,acridiidae1 #hj4 ,alder-fly1 larva of1 #agg2 pupa of1 #ahb4 ,american ,cockroach1 #gd4 ,amphipods1 #ada2 ,rev4 ,t4 ,r4 ,r4 ,stebbing on1 #ada4 ,aquaria1 description of1 #bj4 ,arachnoidea1 #if4 ,argyroneta aquatica1 #ajh2 ,de ,geer on1 #aji2 nest of1 #aaj4 ,arthropods1 #bg2 divisions of1 #bh2 description of1 #bi4 ,ascidians1 ,darwin on1 #ac4 ,asellus aquaticus1 description of1 #aec4 ,assassin ,worm1 #aeh4 ,aurivillius1 ,dr41 on ,crabs1 #aej4 ,bate and ,westwood on ,gammarus1 #adg2 on ,talitrus1 #aea4 ,bateman1 ,rev4 ,g4 ,c41 on ,hydrophilus1 #ej2 on ,nepa1 #ia2 on ,china ,marks1 #aga4 ,beakers1 #ba4 ,beetle ,mite1 #aai4 ,belt on ,blatta1 #fg4 ,black ,beetle1 #fc4 ,black-bobs1 #fd4 ,blackwall on ,spiders1 #aja1 #ajb4 ,blatta orientalis1 description of1 #fc1 #ff2 ,gilbert ,white on1 #fd2 ,dr4 ,sharp on1 #fe2 ,belt on1 #fg2 ,sir ,j4 ,lubbock on1 #fh2 anatomy of1 #fh2 breathing of1 #gj2 ,swammerdam on1 #gd2 ,professor ,plateau on1 #gd4 ,book ,scorpions1 #if4 ,brachelytra1 #ei4 ,broad-clawed ,porcelain ,crab1 #aci4 ,brown ,china ,mark1 #agb4 ,brushes1 #bc4 ,bugs1 #hf4 ,burgess1 ,mr41 on larva of ,dytiscus1 #afj4 ,butler1 ,dr41 on ,spiders1 #ajj4 ,butler1 ,mr4 ,e4 ,a41 on ,forficula1 #gi4 ,capsules1 #ba4 ,carcinus maenas1 description of1 #acf4 ,centipedes1 #abb2 marine1 #abe4 ,cerci1 #dg4 ,chelate1 meaning of word1 #acb n4 ,china ,marks1 #aga2 ,rev4 ,g4 ,c4 ,bateman on1 #aga2 ,de ,geer on1 #agb4 ,cockroach1 #fc4 ,cocktail ,beetle1 #eg4 ,coleoptera1 #cb4 ,collecting1 method of1 #be4 ,corixa1 #id2 ,graber on1 #ie2 ,sir ,j4 ,lubbock on1 #ie4 ,crab1 ,shore1 #acf2 ,porcelain1 #aci4 ,crane-fly1 #afe4 ,crustacea1 #abh4 ,daddy-longlegs1 #ajc4 ,dallas on ,ocypus1 #fa4 ,darwin on microscopes1 #ab2 on ,ascidians1 #ac4 ,devil's ,coach ,horse1 #eg4 ,dipping-tubes1 #bc4 ,dissecting microscope1 #ah4 ,dissection1 mode of1 #cg4 ,diving ,spiders1 #ajh4 ,dugs on ,water ,mites1 #aag4 ,dung ,beetle1 #aai4 ,dytiscus marginalis1 #ca2 etymology of1 #cc n42 breaking of shells by1 #cc2 ,sowerby on1 #cd2 description of1 #ce2 food of1 #cf2 anatomy of1 #cg2 habits of1 #da2 ,kirby on1 #da2 ,sir ,j4 ,lubbock on1 #db2 ,professors ,lowne and ,miall on1 #de2 ,dr4 ,sharp on1 #dg2 abdomen of1 #dg2 breathing of1 #dh2 larva of1 #aeg2 ,swammerdam on1 #aeh1 #aei2 ,mr4 ,burgess on1 #afj4 ,earwig1 #ge4 ,edriophthalma1 #abi4 ,elytra1 #da4 ,epeira diadema1 description of1 #ih2 web of1 #ih2 ,j4 ,a4 ,thomson on1 #ajj2 ,dr4 ,butler on1 #ajj2 ,blackwall on1 #aja1 #ajb2 mode of taking its prey1 #ajb2 ,hudson on1 #ajc2 feet of1 #ajd2 spinnerets of1 #aje4 ,evans1 ,w41 on ,sialis1 #agg4 ,field1 the1 quoted1 #cc1 #ce4 ,forceps1 #bb4 ,forficula auricularia1 #ge2 ,kirby and ,spence on1 #gf2 ,de ,geer on1 #gf2 young of1 #gf2 forceps of1 #gg2 anatomy of1 #gg2 ,butler on1 #gi2 ,dr4 ,sharp on1 #gi4 ,formalin1 #bd4 ,forty-legs1 #abb4 ,fresh-water ,shrimp1 #adb4 ,gamasus coleoptratorum1 #aai4 ,gammarus marinus1 #adf2 ,dr4 ,j4 ,salter on1 #adg4 ,gammarus pulex1 #adb2 anatomy of1 #add4 ,geer1 ,de1 on ,forficula1 #gf2 on ,locusta1 #hj2 on ,water ,mites1 #aaf2 on ,beetle ,mites1 #abj2 on ,lithobius1 #abc2 on ,julus1 #abf2 on larva of ,limnobia1 #afg2 on ,paraponyx1 #agb4 ,geophilus1 #abd4 ,geophilus crassipes1 #abe2 ,mr4 ,pocock on1 #abe4 ,glass block1 #bb4 ,glass box1 #bb4 ,glass slips1 #bb4 ,gosse on ,prawns1 #acc4 ,graber on ,corixa1 #ie4 ,grasshopper1 ,great ,green1 #hj4 ,great ,water ,beetle1 #di4 ,hart1 ,mr41 on ,paraponyx1 #agc4 ,harvestmen1 #if4 ,hemiptera1 #hf4 ,hill1 ,dr41 on ,nepa1 #ij4 ,hudson on ,spiders1 #ajc4 ,hundred-legs1 #abb4 ,hunting ,spiders1 #ih4 ,hydrachna1 #aac4 ,hydrachna globula1 #aah n4 ,hydrophilus1 larva of1 #afd2 ,lyonnet on1 #afd4 ,hydrophilus piceus1 #di2 ,bateman on1 #ej2 legs of1 #ec2 ,simmermacher on1 #ec2 breathing of1 #ed2 cocoons of1 #ed2 ,lyonnet on1 #ed4 ,hymenoptera1 wings of1 #agj4 ,idotea1 #adc4 ,idotea pelagica1 #aee4 ,illinois ,state ,laboratory1 mode of collecting in1 #be4 #8,insects1' #bg2 divisions of1 #cb4 ,invertebrates1 #bh4 ,isopods1 #aeb4 ,julus1 #aba1 #abd4 ,julus terrestris1 #abf2 ,de ,geer on1 #abf2 ,dr4 ,sharp on1 #abf4 ,jumping ,spiders1 #aje4 ,kew1 ,mr41 on dispersal of shells1 #acj4 ,kirby on ,dytiscus1 #da2 on ,ocypus1 #ei2 on ,forficula1 #gf2 on ,locusta1 #hc2 on insect noises1 #hd2 on ,salticus1 #ajg4 ,knives1 #bd4 ,land ,bugs1 #hf4 ,leaping ,orthoptera1 #gi4 ,leitz1 lenses of1 #af4 ,lichtenstein on ,locusta1 #hc4 ,limnaea broken by ,dytiscus1 #cc4 ,limnobia replicata1 larva of1 #afe2 ,de ,geer on1 #afg2 pupa of1 #afh4 ,lithobius forficatus1 #abb2 ,de ,geer on1 #abc2 ,dr4 ,sharp on1 #abc4 ,locusta viridissima1 #hj2 ,dr4 ,sharp on1 #hj1 #he2 ,de ,geer on1 #hj1 #hc2 ,westwood on1 #ha2 ,kirby on1 #hc2 ,lichtenstein on1 #hc2 ear of1 #he4 ,locustidae1 #hj4 ,lowne1 ,professor1 on ,dytiscus1 #de4 ,lubbock1 ,sir ,j41 on ,dytiscus1 #db2 on ,blatta1 #fh2 on ,corixa1 #ie2 on ,opossum ,shrimp1 #ace4 ,lyonnet on larva of ,hydrophilus1 #afd2 on ,ptychoptera1 #ahf4 ,magnification1 power of1 #ae n4 ,mainland1 ,mr4 ,g4 ,e41 on ,water ,mites1 #aah4 ,malacostraca1 #abh2 ,rev4 ,t4 ,r4 ,r4 ,stebbing on1 #abh4 ,margined ,water ,beetle1 #ca4 ,masking ,crabs1 #aej4 ,melicerta janus1 #aej4 ,miall1 ,professor1 on ,dytiscus1 #de2 on ,sialis larvae1 #agi1 #aha4 ,microscopes1 use of1 #aa2 description of1 #ae4 ,millepedes1 #aba1 #abe4 ,mites1 description of1 #aab4 ,model1 a calico1 #cj4 ,myriapods1 #if1 #abj4 ,mysis1 #ace4 ,nature ,notes on ,millepedes1 #aba4 ,needles1 #bc4 ,nepa cinerea1 #hf2 mode of keeping1 #hh2 ,swammerdam on1 #hi2 ,dr4 ,hill on1 #ij2 ,rev4 ,g4 ,c4 ,bateman on1 #ia2 anatomy of1 #ia4 ,noises made by insects1 #hd4 ,notonecta glauca1 #ic4 ,ocypus olens1 #eg2 ,kirby on1 #ei2 as a pet1 #ei2 ,dallas on1 #fa2 larva of1 #fa4 ,opossum ,shrimp1 #ace2 ,sir ,j4 ,lubbock on1 #ace4 ,orchestia littorea1 #aea4 ,orthoptera1 #fc4 ,ovipositors1 #hb4 ,palaemon serratus1 #abi4 ,palaemonetes varians1 #acj4 ,paraponyx stratiotata1 #aga2 ,de ,geer on1 #agb2 ,mr4 ,hart on1 #agc2 anatomy of1 #agd4 ,peripatus1 #cj2 ,professor ,sedgwick on1 #ca4 ,periplaneta americana1 #gd4 ,pholcus1 #ajc4 ,phylum1 definition of1 #bg4 ,planorbis broken by ,dytiscus1 #cc4 ,plateau1 ,professor1 on ,blatta1 #gd4 ,pocket lens1 description of1 #ac4 ,pocock1 ,mr41 on ,geophilus1 #abe4 ,podophthalma1 #abi4 ,porcellana platycheles1 #aci4 ,prawns1 #abi2 ,gosse on1 #acc2 ,sowerby on1 #acc4 ,ptychoptera1 larva of1 #ahb2 pupa of1 #ahg2 ,raumur on1 #ahe2 ,lyonnet on1 #ahf4 ,quekett ,microscopical ,club1 incident at1 #bj4 #8,rat-tails1' #ahb4 ,raumur on ,ptychoptera1 #ahe4 ,robertson1 ,mr41 on ,talitrus1 #aea4 ,salter1 ,dr4 ,j41 on ,gammarus1 #adg4 ,salticus scenicus1 #aje2 ,kirby and ,spence on1 #ajg2 foot of1 #ajh4 ,sand-hopper1 #aea4 ,scorpions1 #if4 ,sedgwick1 ,professor1 on ,peripatus1 #ca4 ,sharp1 ,dr41 on ,dytiscus1 #dg2 on ,blatta1 #fe2 on ,forficula1 #gi2 on ,locusta1 #hj1 #he2 on ,lithobius1 #abc2 on ,julus1 #abf2 on wings of ,hymenoptera1 #agj4 ,shells broken by ,dytiscus1 #cc2 ,mr4 ,kew on dispersal of1 #acj4 ,shore ,crab1 #acf4 ,shore-hopper1 #aea4 ,shrimp1 #acb4 ,sialis lutarius1 larva of1 #agg2 ,w4 ,evans on1 #agg2 anatomy of1 #ahj2 pupa of1 #ahb4 ,sicarius1 #aeh4 ,simmermacher on ,hydrophilus1 #ec4 ,sirex1 #hb4 ,sowerby1 ,g4 ,b41 on ,dytiscus1 #cd4 ,sphaerium1 #acj4 ,sphaeroma1 #aee4 ,spiders1 general description of1 #if2 ,trap-door1 #ig2 ,hunting1 #ih2 ,garden1 #ih2 ,jumping1 #aje2 ,diving1 #ajh4 ,stebbing1 ,rev4 ,t4 ,r4 ,r41 on etymology of ,dytiscus1 #cc n42 on ,malacostraca1 #abh2 on meaning of chelate and sub-chelate1 #acb n42 on ,amphipods1 #ada4 ,stewart1 ,professor1 incident of1 #bj4 ,stilopyga1 #fc4 ,swammerdam on ,blatta1 #gd2 on ,nepa1 #hi2 on ,water ,mites1 #aad2 on ,woodlice1 #aef2 on ,dytiscus larva1 #aeh1 #aei4 ,tailed ,wasp1 #hb4 ,talitrus locusta1 #aea2 ,bate and ,westwood on1 #aea2 ,mr4 ,robertson on1 #aeb4 ,tanypus1 larva of1 #agf4 ,tegetmeier1 ,mr4 ,w4 ,b41 on destruction of shells1 #cd4 ,thomson1 ,j4 ,a41 on ,spiders1 #ajj4 ,trap-door ,spider1 #ig4 ,vertebrates1 #bh4 ,wart-eater1 #ha4 ,water ,beetle1 ,margined1 #ca2 the ,great1 #di4 ,water ,boatman1 #ic4 ,water ,bugs1 #hf4 ,water-devil1 #aeg4 ,water ,mites1 #aac2 ,swammerdam on1 #aad2 ,de ,geer on1 #aaf2 ,dugs on1 #aag2 ,mainland on1 #aah4 ,water ,scorpion1 #hf4 ,water-tiger1 #aeg4 ,westwood on ,locusta1 #ha4 ,white1 ,gilbert1 on ,blatta1 #fd4 ,wing-cases1 #da4 ,wireworm1 #abf4 ,wood1 ,rev4 ,j4 ,g41 on lens stand1 #ae4 ,woodlice1 #aee2 ,swammerdam on1 #aef4 ,worms1 #bi4 ,wright1 ,mr4 ,l41 on microscopes1 #af4 ,zeiss1 lenses of1 #ae4 ,,the ,,end4 ,,footnotes3 #a ,darwin1 ,descent of ,man 7#bnd ed471 p4 #aei1 note #bc4 #b ,the power of magnification of a lens is the ratio of its focal distance to #aj inches4 ,thus a lens of #a inch focus 7or focal distance7 magnifies #aj times 7written #aj1 or ten diameters72 one of in4 focal distance1 #bj times1 and so on4 #c ,a ,popular ,handbook to the ,microscope1 p4 #ci4 #d ,journal of the ,quekett ,microscopical ,club1 v4 #adh4 #e ,ponds and ,rock ,pools1 p4 #ag4 #f ,bulletin of the ,illinois ,state ,laboratory of ,natural ,history1 iv4 #aeh4 #g #8,dytiscus' is written of set purpose4 ,it is not1 as some people tell us1 a miswriting for ,dyticus2 but a properly formed diminutive1 from the ,greek duts a diver2 like paidiskos a little boy4 ,linnaeus consistently calls the genus ,dytiscus from #agce onwards4 ,dyticus only dates from ,geoffroy's ,histoire ,abrge des ,insectes1 first published anonymously in #agfb4 ,on this question of nomenclature ,i am glad to have the support of the ,rev4 ,t4 ,r4 ,r4 ,stebbing1 ,f4,r4,s41 who1 in answer to my inquiries1 kindly wrote1 #8,darwin uses 8,dytiscus0 in the ,origin of ,species1 and ,i should decidedly recommend its being upheld4' #h ,april #d1 #ahif4 #i ,popular ,history of the ,aquarium1 p4 #beh4 #aj ,may #b1 #ahif4 #aa ,international ,science ,series1 ,no4 lxv4 #ab ,aquatic ,insects1 pp4 #ee1 #ef4 #ac ,zeitschrift f4 wiss4 ,zoologie1 ,bd4 xl4 ,s4 #dha4 #ad ,mmoires du ,musum d'histoire naturelle1 xviii4 #ded sqq4 #ae ,i have purposely given ,blatta as the generic name1 rather than ,stilopyga1 which should properly be used1 as the former is only employed in very recent literature4 #af ,miall and ,denny1 ,the ,cockroach1 p4 #bj4 #ag ,cambridge ,natural ,history1 v4 #bca4 #ah ,the ,senses of ,animals1 p4 #dd4 #ai ,cambridge ,nat4 ,hist4 v4 #bbc4 #bj ,book of ,nature1 p4 #id4 #ba ,this refers to the gizzard4 ,echinus was used to denote the third stomach of ,ruminants 7now called the manyplies71 because it was thought to resemble a hedgehog rolled up4 #bb ,miall and ,denny1 ,the ,cockroach1 p4 #aah 7note74 #bc ,introduction to ,entomology1 letter xi4 #bd ,proceedings of the ,zoological ,society1 #ahib1 p4 #ehf4 #be ,our ,household ,insects1 pp4 #aei-afc4 #bf ,kirby and ,spence1 ,introd4 to ,entomology1 ed4 #ahgj1 p4 #dhd4 #bg ,cambridge ,natural ,history1 v4 #cah4 #bh ,the ,senses of ,animals1 p4 #ge4 #bi ,j4 ,arthur ,thomson1 ,outlines of ,zoology1 p4 #bhh4 #cj ,science for ,all1 ii4 #agh4 #ca ,british ,spiders1 p4 #aj4 #cb ,british ,spiders1 p4 #cei4 #cc ,naturalist in ,la ,plata1 p4 #ahh4 #cd ,mmoires1 vii4 p4 #cjd sqq4 #ce ,book of ,nature1 pp4 #aja1 #ajb4 #cf ,mmoires1 vii4 #add1 #ade4 #cg ,the specimen was kindly identified for me1 by ,dr4 ,trouessart of ,paris1 as a nymph of ,hydrachna globula 7,dugs71 and has been deposited in the ,british ,museum 7,natural ,history74 #ch ,mmoires1 vii4 #abc-abh4 #ci ,cambridge ,natural ,history1 vol4 v4 ch4 ii4 #dj ,nature1 ,dec4 #ab1 #ahie4 #da ,mmoires1 vii4 #efi4 #db ,crustacea1 p4 #g4 #dc ,crustacea1 p4 #bbe4 #dd ,international ,science ,series1 ,no4 lxxv4 #de #8,a limb is chelate when it has joints that will act together like a pair of tongs4 ,generally this character is produced by the hinging of the seventh joint a considerable way down on the side of the sixth4 ,when the seventh joint1 or finger1 can be folded back upon the sixth1 although the latter is not produced into any thumb-like process to oppose it1 the limb is then said to be sub-chelate1 the claw being in that case partial1 though often extremely efficient4' ,stebbing1 ,crustacea 7,international ,science ,series1 lxxiv71 p4 #de4 #df ,popular ,history of the ,aquarium1 p4 #bbc4 #dg ,lubbock1 ,senses of ,animals 7,international ,science ,series1 lxv471 p4 #ic4 #dh ,aquarium 7ed4 #ahef71 pp4 #da1 #db4 #di ,crustacea 7,international ,science ,series1 lxxiv71 pp4 #h1 #i4 #ej ,bate and ,westwood1 ,british ,sessile-eyed ,crustacea1 i4 #h4 #ea ,trans4 ,connecticut ,academy 7#ahhb71 iv4 #bgd1 #bge1 note4 #eb ,ponds and ,rock ,pools1 p4 #aah4 #ec ,british ,sessile-eyed ,crustacea1 i4 #ba4 #ed ,proceedings ,nat4 ,hist4 ,soc4 ,glasgow1 vol4 i4 pt4 ii4 n4 s4 pp4 #acj-acb4 #ee ,british ,sessile-eyed ,crustacea1 ii4 #cha4 #ef ,book of ,nature1 i4 #agd4 #eg ,mmoires1 iv4 #chf4 #eh ,proceedings ,boston ,society of ,natural ,history1 xxi4 #bbc-bbh4 #ei ,natural ,history of ,aquatic ,insects1 p4 #dg4 #fj ,mmoires du ,museum1 xviii4 #ddb1 #ddc4 #fa ,mmoires1 vi4 #ceb-ee4 #fb ,diptera1 iii4 #bha4 #fc ,cambridge ,natural ,history1 v4 #did4 #fd ,mmoires pour servir1 i4 #egg sqq4 #fe ,bulletin of the ,illinois ,state ,laboratory of ,natural ,history1 iv4 #afg4 #ff ,w4 ,evans1 ,trans4 ,entomol4 ,soc4 7,london71 iv4 #bfa4 #fg ,mmoires pour servir1 t4 vi4 ,plate #ca4 #fh ,mmoires du ,musum1 t4 xix4 pp4 #ajc1 #ajd4 ,transcriber's ,notes3 #a4 ,obvious printers'1 punctuation and spelling errors have been corrected silently4 #b4 ,some hyphenated and non-hyphenated versions of the same words have been retained as in the original4 #c4 ,superscripts are represented using the caret character1 e4g4 ,dr4 or ,xxx4 #d4 ,italics are shown as xxx4