258 



THE CEPHALOPHORA. 



^227. 



It is only lately, that, from microscopical analyses of the contents of 

 these parts, this point has been made clear. A peculiarity which distin- 

 guishes principally the Pteropoda, Apueusta, Nudibranchia, Inferobran- 

 chia, Tectibranchia, and Pulmonata, is the existence of a hermaphrodite 

 gland. An exact knowledge of the structural relations of this gland has 

 been the means of reconciling the hitherto confused opinions upon the geni- 

 tal organs of the Cephalophora. 



This gland, which is nearly always buried in the substance of the liver, 

 is composed of digitiform or botryoidal ramose caeca, bound together in 

 groups of variable size forming a lobulated organ. Upon each caecum is 

 an external sac, producing eggs, and an internal one, folded in the first, 

 producing sperm. The walls of these two invaginated follicles are usually 

 in direct contact, and are not separated from each other except at the 

 points where there are eggs which push the ovarian sac outwards and the 

 testicular one inwards.'-* 



From these sacs pass off excretory canals, which, also, are invaginated, 

 and terminate in two principal ducts, the external of which is the 

 Tuba FaZ/opii, and the intei'nal the Fas (^e/ere/ts which is usually tortuous. '^^ 



attributes to this last the function of an ovary 

 (Beitr. zur Anat. d. Ilelicinen, loc. cit.), has ex- 

 pressed no positive opinion as to tlie function of 

 the albumen gland. Steenstrup (Undersogelser 

 over Ilermaphroditismens Tilvaerelse i Naturen, 

 1845, p. 76, Tab. II.) has expressed a very singu- 

 lar opinion on the subject of the genital organs of 

 the Pulmonata. He regards the Gasteropoda as 

 of separate sexes with which the different parts of 

 the genital apparatus are double, and that only one 

 side is developed, the other remaining atrophied as 

 in female birds. According to this, the hermaphro- 

 dite gland would represent the active ovary, in the 

 individuals which Steenstrup regards as females, 

 and the albumen-gland would be the ovary on the 

 other side imperfectly developed. The uterine canal 

 would belong to the active side, the Kas deferens 

 would be the abortive uterus on the other side, and 

 the penis as an abortive analogous vesicle would 

 correspond to the pedunculated vesicle of the active 

 side. 



In the other individuals of the same species re- 

 garded by Steenstrup as males, the hermaphro- 

 dite gland would be the active testicle, and the al- 

 bumen-gland, the same organ on the other side, 

 abortive ; the uterus would be the developed l^'as 

 deferens, and the proper Fas deferens the unde- 

 veloped organ on the other side. The pedunculated 

 vesicle would have the same signification as with 

 the female individuals, and the penis would be this 

 vesicle imperfectly developed.* 



2 After /J. IVagner {(Viegmann''s Arch. 1836, 1, 

 p. 370) had found in various Pulmonata, eggs and 

 spermatic particles at the same time in one and the 

 same genital gland, and I myself had expressed my 

 conviction (Ibid. 1837, I. p. 51) that with these 

 Gasteropoda the ovary and testicle were united 

 in a single organ, H. Meckel was the first who de- 



* [§ 227, note 1.] This structure — a hermaph- 

 rodite gland — is not mentioned by Alder and Han- 

 cock in their anatomical details of the Nudi- 

 branchia; see loc. cit. With those genera (Jto/j«, 

 Doris, &c.) with which they have given m special 

 detiiil the generative organs, this combination of 

 the two sexual organs is not spoken of. 



See especially Hancock and Embleton^s Anat- 

 omy of Aeolis, Ann. Nat. llist. I. 1848, p. a3, 



scribed exactly the structure of this hermaphrodite 

 gland (^Mailer's Arch. 1844, p. 483, Taf. XIV. XV). 



It is, therefore, astouisliing that Steenstrup 

 (Undersogelser, &c., p. 76,' Tab. II. fig. 3,4), who 

 knew the researches of Meckel, and who, judging 

 from his figures, saw distinctly the line of separa- 

 tion between the ovarian and testicular follicles, 

 has determined two fragments of this gland taken 

 from different individuals of Helix pomatia, 

 as bemg one an ovary, and the other a testicle. In 

 this last-mentioned fragment, he has called sperm- 

 atic cells not only those really such of the internal 

 follicle, but also the eggs contained in the external 

 follicle ; while in the first-mentioned fragment, or 

 the so-called ovary, he has named as eggs not only 

 the real eggs but also the internal spermatic cells. 

 The spermatic particles, which he also saw at the 

 same tune, would, according to him, be brought out 

 by coition. 



3 Under the Pteropoda, Kolliker (Denkschrift. 

 &c. VIII. p. 39) has found the hermaplu-odite 

 gland with Hyalea. From this, the organs de- 

 scribed by Cuvier, Esc/iricht, and Fan Beneden, 

 (loc. cit.), as ovaries and oviducts with Clio, Cym- 

 bulia, Cleodora, Cuvieria, Limacina, kc, may 

 be regarded as an hermaphrodite gland, and as 

 invaginated excretory canals. Under the Apneus- 

 ta, this gland has been seen by Kolliker, with 

 Aeolis, Lissosoma, and Flabellina. It exists 

 also with Actaeon, judguig from the description 

 of Allmann (loc. cit. p. 152, PI. VI. VII. fig. 8) 

 of its voluminous and multiramose ovaries, in 

 which, he says there are observed,' beside the pro- 

 jecting sacs filled with eggs, others smaller filled 

 with a granular substance. The first are very 

 probably ovarian, and the others testicular follicles. 

 Tergipe.s, also, has a similar ramified ovary ; but 

 it was incorrectly interpreted by Nordmann (loc. 



where the androgynous apparatus is minutely de- 

 scribed. 



These authors affirm that although self-impreg- 

 nation is, perhaps, possible, yet there is usually a 

 congress of two individuals, and therefore a recip- 

 rocal copulation. 



See also upon this point, — the real relations of the 

 hermaphrodite gland, Qratiolct, Jour, de Conchol. 

 1S50, No. II. p. 116. — Ed. 



