360 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 deferentia, which are dilated, near their extremity, into 

 a nearly strai^t Ductus ejaculatorius.*^'''' The excretory ducts of the sperm 

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

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

 of these ducts, is divided 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 excretory ducts almost invariably open on the coxal 

 joint of t^;^ 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 Brachyura 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 (secondai'y 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- 

 it With Astacus ; see Roesel, loc. cit. Taf. V. Taf. III. fig. 12 {Astacus). In this last ge- 

 LVIII. fig. 9, and Taf. LX. fig. 23 ; Suckow, loo. nus, these organs are slightly spiral at their extrem- 

 cit. Taf. X. fig. 15 ; Brandt, Mediz. Zool. II. Taf. ity. These penises are long, secondary, and con- 



XI. fig. 14 ; Milne Edward!^, Hist. d. Crust. PI. cealed under the tail with the male Brachyura and 



XII. fig. 14 ; and Cams, Erlauterungstaf. Heft. V. Anomura, witli which the majority of the other 

 Taf. III. fig. 9. anal feet are wanting ; see Milne Edwards, Hist. 



20 These spermatophores, first made linown by d. Crust. I. p. 169, i"!. III. fig. 6, 15, 16 (Maia) ; 

 KoUiker, are bound together, with Galathea, by in tliis genus tlie two pairs of anal feet are rudi- 

 ramified pedicles ; and with Pagurus, by simple mentary. This abortion is observed, also, with 

 filaments ; see KoUiker, Beitr. zur Kenntniss d. Grapsus, Cancer, Lupea, Ocypoda, Porcellana, 

 Geschlechtsv. &c. p. 9, fig. 21, 22, also, Sehweiz. &c. See the beautiful figures of Savigny, in 

 Denksch. VIII. p. 52, fig. 32-35. See, also, the Descript. de I'ilgypte, Crust. PI. II.-VII., and 

 description which I have given of the spermato- Cavolini, loc. cit. Taf. II. fig. 10 (Grapsus). With 

 phores of Pagurus Bernhardus, in MiiUer's Arch. Dromia, the two feet of the sec )nd caudal segment 

 1842, p. 136, note 1. But one must be careful not have the form of two long s])ines. With Hornola, 

 to take, in the testicles of the Decapoda, the mothei-- the same feet are equally pedicellated, but termi- 

 cells in which are developed the radiating cells for uate with a kind of sucker, and, therefore, are un- 

 tlie spermatophores. doubtedly auxiliary in the act of copulation. No 



21 The land crabs make an exception in this re- auxiliary organs have been found with Galathea, 

 spect, their male genital orifices being situated on Palinurus, and Scyllarus ; but in the last two 

 the last segment of the body ; see Milne Edwards, of these genera the feet of the first caudal segment 

 Hist. Nat. d. Crust. I. p. 168, PI. XVIII. fig. 6 are wholly wanting. With the Caridoidae, the 

 {Gecarcinus). copulatory organs are usually absent, and the first 



22 For Astacus, see the figures cited above ; for pair of anal feet does not differ from the others ; 

 Palinurus, Milne Edwards, Hist. d. Crust. PI. with Crangon, only, have I found the internal pro- 

 XXIII. fig. 2 ; and for Hippolyte, Kroyer, loc. longation of these leet highly developed and gla- 

 cit. p. 27, fig. 54, B. f. brous ; while with the posterior feet, it is very 



23 There are two very short, and soft penises small, and, like the external one, very hairy. Ac- 

 with Mala, Pisa, Cancer, Grapsus, Lupea, cording to Joly (loc. cit. p. 43, PI. III. fig. 20), it 

 Gecarcinus, Porcellana, ffomola, &c. They are is somewhat similar with Caridina. Krdyer (loc. 

 long, hard, and point forwards with Dromia. cit. p. 27, PI. II. fig. 54, B. g.) has observed, with 



24 The canaliculated, secondary penises may be Hippolyte, between the feet of the fourth pair, two 

 very easilj' seen on the first caudal segment of short hooked appendages which may be regarded 

 Homarus, Nephrops and Astacus; see Roesel, loc. as secondary penises. 



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



