N S E C T S. 



venils. fhe tedis is ulii'.ifh, and has a glandular appear- 

 •Bucc, In the ci'abs the two canals are very larg^ near the 

 penifes, become afterwards (lender, and are lb convoluted as 

 to form the appearance of a gland on each fide. Thefe 

 rglands are not united. 



In the common lobfter tlie two ovaria are joined, fo as to 

 .form a fingle one to all. appearance. The two ovidudls are 

 Jhort, ftraight, and go direitly to the vulvae : the latter are 

 iimple holes pierced in the fiibllance of the corfelet, near the 

 third pair of fact in tlie crab, and in tl.e very bafis of tliis 

 tliird pair in the lobiier and hermit crab. 



The female cruilacea attach their eggs, after laying them, 

 to the filaments of the fins under the tail, and carry them in 

 tliat fituation until they are liatched. 



Organs af GenercUon in the proper Iiifcds.— Ths external 

 parts are fimple, and placed at the pofterior e.Ktremity of the 

 body in moil infcds. To this rule there are feme excep- 

 tions, both in number and pofition. In tlie fpidcrs they are 

 double ; and the male organs are placed on the maxillary 

 palpi ; the phalangia have a fimple male organ, coming out 

 from the root of the abdomen. 



The libellula: have the male organ at the bafi?, and not at 

 the point of the abdomen ; and hence ariies their very fin- 

 gular attitude in copulation. The male faizec the neck of 

 the female with the hooks at the extremity of his abdomen, 

 until the female bends herfclf back, and brings the extremity 

 of her own abdomen to the bafis of that of the male. 



The generative organs of the luli are about the middle of 

 the body. 



I. Male Organs. — Tiiefe confifl in general of a penis with 

 its coverings, of a common fpermatic canal, and of two pairs 

 of organs, which may be regarded as tefticles and veficula; 

 feminales. Each of thefe pairs may be more or lefs fubdi- 

 vidcd ; they vary in figure and in lize. 



I. In the Cohoptera. 



a. In the LameUkcrn'ia. — The genera feparated from the 

 fearabsi nt Linnseus, as the melolonthje, cetoniae, trichis, 

 fcarabxi, &c. have numerous globular te!lic!es and veficulse 

 in the form of tubes, as flender as threads, and exceffively 

 long. In the fcarabxus naficornis, for example, the two vefi- 

 cula feminales are more than twenty times the length of the 

 body, and are convoluted into a packet or mafs, wiiich it is 

 not very difRcult to unravel. Their tube is a little enlarged 

 before it joins the common canal. On each fide there are fix 

 tefticles of a fmall fize, and producing each an excretory 

 tube mere (lender than a hair: thefe fix fmall tubes are 

 united into one canal, whicli is joined to that of the op- 

 pofite fide precifely at the point where the vefieulx feminales 

 are united. The common canal, refulting from thefe four 

 tubes, becomes large and mufcular, and then goes into a 

 horny fheath, terminated by a -kind of pincers, between the 

 laminjs of which the penis is placed. The latter is merely a 

 fmall cylindrical tube. It appears tisat llie two branches of 

 the pincer are introduced into the vulva, and then feparated 

 fo as to facilitate the entrance of the penis Swammerdam 

 has given a very accurate figure of thefe parts. 



The melolontha refembles the S. naficonus. 



The organs are more complicated in the cetonia : there 

 are twelve tefticles on each fide, and, belides the filiform 

 veficulsp, which are probably tliirty times as long as the 

 body, there are two other (hort and thick pairs ; the fliorteft 

 of the latter has its extremity forked. The canals of the 

 three pair.< of veficulx, as well as the canals of the two 

 groups of te.fticles, join together at the fame point to con- 

 ftitute the common fpermati;; tube, wliich goes to tlie 

 pcni.. 



Vw.= XLX. 



The trichise refemblc the cetoni:e. 



The coprides, or dung beetles, and tlio lucani, or ftag 

 beetles, do not follow the fame type : they have only one 

 tefticle on each fide, and this is a globular and compact mafs 

 made up of the convolutions of a fingle tube. Their vefi- 

 culse feminales arc alfo filiform, but not fo long in proportion 

 as thofe of the fcarabaei. 



b. In the Carnivora. — The organs are' very fimple in the 

 dytifcus ; there are two large veficul.e of moderate length, 

 very little convoluted ; two globular tefticles covered by a 

 yellowi(h matter, which may be removed ; they are tlien 

 eafily unravelled into a fingle, filiform, flender and longvefrd. 

 Tlie vas deferens is merely the contifiuation of this : it en- 

 ters the veficula a little before that joins the o])pofite tube 

 to form the common fpermatic canal. 



c. In thi C/aficoriiia—The lUv.tWre of the hyt'rophi'us 

 is more complicated than that of the dytifcu.s : it has two 

 oval tefticleSj each of which is formed by the convolutions of a 

 fingle veffel. The vas deferens, which is as fiiie as a hair, fwells 

 into a fmall oval veficle where it ends in the common canal. 

 The principal veficulae feminales are large, with ftrong fides, 

 fpiialiy convoluted, and terminating fuddenly in a fmall 

 veflcl folded in zig-zag, and forming the appearance of an- 

 other fmaller tcllide. There are, moreov-r, two acceflbr-y 

 veficulx, with thin fides, each divided into three branche.'., 

 and into fome fmall blind appendices. The common fpjiK- 

 matic canal has a mufcular enlargement towards its middle, 

 and becomes again fuddenly fmall to enter the penis. Tliele 

 parts are figured by Swammerdam, but rather rudely. ■ 



The filpha atrata has two large oval tefticles, formed of 

 an infinite nuiv.ber of fmall fiiort veffels, ivfembling thofe 

 brufiics of which the hairs project in every dirtClion. The 

 vas deferens is fmdl and (hort. There are tv.-o pairs o*' 

 veficula-, both cylindrical and tolerably large ; one of them 

 is folded in a ferpentine manner round the intelliue, and 

 may be four or five times the length <f,i the body : the 

 other is much ftiorter. The common fpermatic canal i« 

 cyhndrical and (hort. The penis is alfo cyhndrical, covered 

 with horny pieces, but has no pincer. An oval bladder, 

 of which the ufe is unknown, but which refembles in its 

 pofition and figure the urinary bladder of the m.ammalia* 

 is found at its internal bafis. 



J. In the Filkornia. — The common fpermatic canal i« 

 eight or ten times the length of the body in the blapS 

 mortifaga ; four organs refembling veficulse are connected 

 to it at its origin. Two of thefe firft make fome verj' re- 

 gular fpiral turns, growing at the fame time fmaller; and 

 then enlarge again and are irregularly folded. The tw» 

 others have a zig-zag courfe, and are mucli ihorter. 



2. In the Orthopf(rj.—'li\i'^ g''}l'' have two,confiderablo 

 oval tefticles attached to the back : they are covered by a 

 yellow mucofity, in which the tracheie may be feen beauti- 

 fully diftributed. . They are compofcd of (mall (hort veilels, 

 which make up a kind of bru(h. The vas deferens is- folded 

 in the form of an epididymis : a little before joining lht» 

 oppofitc one, to form the common canal, it is enlarged, bu.* . 

 caufe it receives two groups of veficulse. One of thefe con- 

 tains more than fixty, and the other above two hundivd inech 

 fmaller than the former. The four bundles fill nearly half 

 the abdomen. Two fmall oval velicles arc found at the verys 

 point of union of the two vafa defcientia. 



3. In the Ilampier.i. — The water fcorpion (nepa fcor- . 

 ploides) has two Iniall, (hort, and cyhndrical veficulx, two 

 large vafa defereiuia convoluted like the epididymis, and' , 

 divided at their origin, each into four Imall tefticles, each 

 of which is again prolonged into a very long lihtorm vef- ' 

 fel. Thefe eight veiTels aie convoluted into a mafs. 



A a " 4./» 



