^291. 



THE CRUSTACEA, 



351 



With very many Crustacea, the sperm, at its emission, is contained in 

 capsules (Spermatop/iores). 



I. Hermaphrodite Critstacea. 



§ 291. 



With the Cirripedia, the male and female genital organs are quite re- 

 moved from each other. With the Lepadea, the ovaries are lodged in the 

 upper extremity of the peduncle and in the midst of the spongy substance, 

 filling its cavity.'^' They consist of ramified caeca, while with the Balano- 

 odea, the ovarian follicles are situated between the lamellae of the mantle/-' 

 With the Lepadea, the canal which extends from the lower extremity of 

 the shell into the peduncle and communicates by a narrow opening with the 

 cavity of the mantle, may properly be regarded as an oviduct.'"' But new 

 researches are required to show by what means the eggs of the Balauodea 

 reach this same cavity, for, as is the case with the Lepadea, they remain 

 there until the embryos are fully formed. These eggs, of a blue or yellow 

 color, are always intimately glued together, and form, after the laying, a 

 large sheet or layer which, with the Balanodea, is applied to the internal 

 surface of the mantle, and often retained there by the branchial lamellae ;'*' 

 while with the Lepadea, it covers, bonnet-like, the rounded portion of the 

 body. 



The Testicles are composed of numerous ramified follicles spread out be- 

 tween the skin and the two sides of the digestive canal. They join from 

 the right and left into two very long and tubular Vasa deferentia which 

 accompany, serpentinely, the alimentary canal to the anus, and then blend 

 together, forming a more narrow Ductus ejaculatorius. As this last trav- 

 erses the whole tail and opens at its extremity, it has been usually regard- 



1 Burmeister (Beitr. p. 46), and fTagner (Mul- 

 ler's Arch. 1834, p. 469, Taf. VIII. fig. 10), were 

 the first to notice the ovarian follicles of the foot of 

 the Lepadea, the first with Otion, the second with 

 Lepas. Martin St. Ange (loc. cit. p. 20, PI. I. 

 fig. 10, 11) has verified this fact witli this last ge- 

 nus. I have found them also in the foot of Cine- 

 ras, and I will remark that in the remaining spongy- 

 substance of this foot, there are other round nucle- 

 ated bodies which ap])ear to be solid concretions, 

 and should n jt be confounded with the genus. 



2 The ovaries of the Balanodea are more difficult 

 of study than those of the Lepadea, probably be- 



cause they are scattered in the walls of the mantle, 

 and consequently scarcely visible, especially when 

 empty. It is undoubtedly on this account that 

 Poll (Testae, utriusq. Sicil. &c. I. p. 19, 28, Tab. 

 IV. fig. 13, .\. X. Tab. V. fig. 13, 15) has taken for 

 ovaries, with a Balanus, the testicular follicles, al- 

 though he distinctly saw and has figured the ovari- 

 an follicles in another species of this same genus. 



3 This canal, regarded as an oviduct by Wagnvr 

 (loc. cit.), had already been mentioned by Cuvier 

 (Mem. loc. cit. p. 4, fig. 4). 



4 With BalanUs, the layers of eggs form usually 

 two large discs {Poli, loo. cit. Tab. IV. fig. 18, c. c). 



figm-es). The nuclear appearance is due, some- 

 times to a depression in the "body (as with Aatac us), 

 sometimes to a plastic membrane lying about one of 

 the spinous processes (as with Pilumnus), all 

 made prominent by the refraction of the light ; see 

 my researches in the Proceed. Boston Soc. Nat. 

 Hist. IV. p. 258. 



In regard to the spermatic particles of the Ento- 

 mostraca, I have examined those of Cypris, Cy- 

 clops, and Daphnia. They are developed, as usual, 

 in special cells — are exceedingly minute, and in 

 form closely resemble those of the Araneae ; consist- 

 ing of an arcuate rod to which is attached a short 

 but very delicate tail. My results, therefore, do 

 not agree with those above-mentioned. 



The whole subject of the spermatic particles of 

 the Crustacea is sadly deficient in well-authenti- 

 cated observations, and particles and cell-like forms 

 are constantly described as spermatic p;uticles, 

 which, according to all the laws of Sperniatnlntry 

 as yet known, cannot be such. It should be re- 

 membered that the spermatic particle is never a 

 cell, but is the metamorphosed nucleus of a cell ; it 

 is, therefore, always a more or less solid corpuscle 

 (whatever be its form, &c.), and to which, moreover, 

 there may be attached one or more ai>penda.gea 

 — Ed. 



