S60 



THE CRUSTACEA. 



«^ 293. 



With other Macrura, the testicles consist only of a trilobed glandular mass 

 covering the pyloric portion of the stomach, and from which pass off two long, 

 very flexuous Vasa defer entia, which are dilated, near their extremity, into 

 a nearly straight D^^fh^s ejaculatoriusj^^^ The excretory ducts of the sperm 

 are very distinct with the Decapoda, when filled with this fluid, from their 

 chalk-white color. With many species, the sperm, as it approaches the end 

 •of these ducts, is (Jivided into portions, around which capsules or spermato- 

 phores are developed. 



These last are usually pyriform, and connected together by a common 

 band.*^*' The external genital organs of the male Decapoda are quite 

 varied, although these excretox-y ducts almost invariably open on the coxal 

 joint of the last pair of feet.*-^' With the Paguridae, and Macrura, the 

 male genital orifices are surrounded by a soft sphincter, without any trace 

 of a penis, but out of which the Ductus ejaculatorius is perhaps pro- 

 truded during copulation.*'"* But with the Brachyui'a and short-tailed 

 Anomura, on the contrary, there are two longer or shorter tubular pe- 

 nises, always covered by the tail, which is pressed against the belly,*-'* 

 With very many Decapoda, the two feet of the first caudal segment are 

 transformed into pedicellated processes (secondary penises), the extrem- 

 ity of which is sometimes grooved. With some short-tailed Anomura, the 

 feet of the second post-abdominal pair take part also in the act of copula- 

 tion, and, for this purpose, are prolonged into stalk-like organs.'-'** 



Among the Myriapoda, the Glomerina have two testicular tubes extend- 

 ing into the abdomen and composed of numerous vesicles partially blended 

 together. They unite in the thorax into a common Vas deferens. With 

 the Julidae, the testicles have a similar structure, but the vesicles open 

 .separately into the external side of the two Vasa deferentia, which are close 

 together, and are connected, in a ladder-like manner, by numerous trans- 



19 With Astacus ; see Roesel, loc. cit. Taf. 

 ■LVIir. fig. 9, and Taf. LX. fig. 23 ; Sucknw, Inc. 

 cit. Taf. X. fig. 15 ; Brandt, Mediz. Zool. II. Taf. 

 Xr. fig. 14; Milne Edwards, Hist. d. Crust. PI. 

 XII. fig. 14 ; and Carus, Erlauterungstaf. Heft. V. 

 Taf. III. fig. 9. 



^ Tiiese si)ermatophores, first made known by 

 KoUiker, are bound togetlier, witli Galathea, hy 

 ramified pedioles ; and willi Pagurun, by simple 

 filaments ; see KoUiker, Beitr. zur Kenntniss d. 

 (Geschlechtsv. &c. p. 9, fig. 21, 22, also, Schweiz. 

 Denksch. VIII. p. 52, fig. 32-35. See, also, the 

 description which I have given of the spermato- 

 j)hores of Pa gurus Bernhardus, in MüUer^s Arch. 

 1842, p. 136, note 1. But one must )je careful not 

 to take, in the testicles of the Decapoda, the mother- 

 cells in which are developed the radiating cells for 

 the spermatophores. 



21 The land crabs make an exception in this re- 

 spect, their male genital orifices being situated on 

 the last segment of the body ; see Milne Edwards, 

 Hist. Nat. d. Crust. I. p. Iü8, PI. XVlll. fig. 6 

 {Oecarcinus). 



Ä! For Aslar.HS, see the figures cited above ; for 

 Palinurus, Milne Edwards, Hist. d. Crust. PI. 

 XXIII. fig. 2 ; and for Uippolyte, Krötjer, loc. 

 •cit. p. 27, fig. 54, B. f. 



ISi There are two very short, and soft penises 

 ■with Ma'ia, Pisa, Cancer, Urapsus, Lupea, 

 Oecarcinus, Porcellana, Homola, &c. They are 

 long, hard, anil point forwards with Dromia. 



'■H The canaliculated, secondary penises may be 

 very easily seen on the first caudal segment of 

 Hoinarus, Neplirops and Astacus; see Roesel, loc. 

 cit. Taf. LVI. ; and Carus, Erlauterungstaf. Heft. 



V. Taf. III. fig. 12 (Astacus). In this last ge- 

 nus, these organs are slightly spiral at their extrem- 

 ity. These penises are long, secondary, and con- 

 cealed under the tail with the male Brachyura and 

 Anomura, with which the majority of the other 

 anal feet are wanting ; see Milne Edwards, Hist, 

 d. Crust. I. p. 169, PI. III. fig. 6, 15, 16 (Maia) , 

 in this genus the two jjairs of anal feet are rudi- 

 mentary. This abortion is observed, also, with 

 Grapsus, Cancer, Lupea, Ocijpoda, Porcellana, 

 &c. See the beautiful figures of Savis^ny, in 

 Descript. de I'Jigypte, Crust. PI. II.-VII., and 

 Cavolini, loc. cit. Taf. II. fig. 10 (Grapsus). AVith 

 Drumia, the two feet of the second caudal segment 

 have the form of two long spines. With Homola, 

 the same feet are equally pedicellated, but termi- 

 nate with a kind of sucker, and, therefore, are un- 

 doubtedly auxiliary in the act of copulation. Nc 

 auxiliary organs have been found with Galathea, 

 Palinurus, and Scyllarus ; but in the last two 

 of these genera the feet of the first caudal segment 

 are wholly wanting. With the Caridoidae, the 

 copulatory organs are usu;Uly absent, and the first 

 pair of anal feet <ioes not ditfcr from the others ; 

 with Crangon, only, have I found the internal pro- 

 longaticjn of these feet highly developed and gla- 

 brous ; while with the posterior feet, it is very 

 small, and, like the external one, very hairy. Ac- 

 cording to Joly (loc. cit. p. 43, PI. III. fig. 20), it 

 is somewhat similar with Caridina. Kroyer (loc. 

 cit. p. 27, PI. II. fig. 54, B. g.) has observed, with 

 Hippotyte, between the feet of the fourth pair, two 

 short hooked appendages which may be regarded 

 as secondary penises. 



