$$ 226, 227. THE CEPHALOPHORA. 20T 
§ 226. 
Among all the hermaphrodite Cephalophora, the genus Sagztia stands 
wholly alone, in having all parts of its genital apparatus double. 
The ovaries consist of two straight, non-ciliated tubes situated at the pos- 
terior extremity of the cavity of the body; these open externally by an 
arcuate oviduct, situated upon the back directly over the median line of 
each of the posterior lateral fins. 
The two internally ciliated testicles fill the caudal cavity, which is 
divided into two chambers by a longitudinal septum. They send backwards 
two short deferent canals, which open in front of the caudal fin, by two tumid 
orifices, but are without copulatory organs. 
§ 207, 
As for the other hermaphroditic Cephalophora, to which belong the 
Pteropoda and a majority of the Gasteropoda, the genital organs of the 
Nudibranchia, Inferobranchia, Tectibranchia, and Pulmonata, have been 
the most thoroughly investigated. But the different divisions of these 
organs have been interpreted in a manner so varied and contradictory, that. 
one can almost despair of having any positive knowledge of their rela- 
tions. 
1 See Krohn, loc. cit. p. 9, fig. 2, 7-9. The cil- 
fated epithelium which covers the male genital 
organs of Sagitta, from the posterior extremity to 
the genital orifice, produces a general up-and-down 
movement of the sperm in the testicle, a phenome- 
non which Darwin has compared to the motions 
of the sup in Chara (Ann. of Nat. Hist. XIII. p. 
3, Pl. I. tig. 1, or Froriep’s neue Notiz. No. 639, p. 
3, Be ee, and Ann. d. Sc. Nat. I. 1844, p. 362, 
Pl XV. B). For the genital organs of Sagitta, 
see also the researches of Wilms (lve. cit. p. 12). 
1 It has been quite difficult to reconcile the fact 
that, with these animals, the testicle and the ovary 
are United i in a single body, —the Hermaphrodite 
gland. Cuvier, whose opinion has been followed 
by Meckel, and Carus, in their different publica 
observed exactly like Ké/liker. Lhave found these 
particles throughout this group, generally, to consist 
of a delicate thread, one end of which is more or less 
incrassated and twisted in a cork-screw manner 
(2£olis, Physa, Lymnaeus, Natica, Helix, Li- 
maz, &c.); in some, however, the form is remarka- 
bly different. Thus, with Buccinum, it consists of a 
thread with a terminal third somewhat incrassated, 
but which terminates in a delicate filament. This, 
as will be seen above, Kéllixer has also noticed. 
As to the remarkable statements made above 
upon two kinds of spermatic particles with Palu- 
dina vivipara, they deserve our especial attention. 
My own investigations have Jed me to regard it as 
a law in Spermatology, that each animal had only 
one kind of spermatic particle, the shape and size of 
which in that animal, are invariably the same ; this 
point I have regarded as so well established that 
I have proposed the basis of an animal classifica- 
tion from spermatological data. I was therefore 
surprised to find an observer like Leydig who has 
22% 
tions, regarded this gland, with the Pulmonata. as- 
an ovary, and the albumen-secreting organ, as a 
testicle. TJ'reviranus (Zeitsch. fur Physiol. I- 
p. 3. V. p. 140) was of the opposite opinion ; he 
considered the hermaphrodite gland as a testi- 
cle and the other as an ovary. This view has 
been adopted by Prevost (Mém. d. 1. Soc. Phys. 
de Genéve, V. p. 119, and Ann. d. Sc. Nat. XXX. 
p. 33, 43), and by Paasch (Diss. loc. cit. and 
Wiezxmann’s Arch. 1843, I. p. 71, 1845, I. p. 34). 
In Eugland, Rymer Jones adopts the view of Cu- 
vier, and Owen that of Treviranus. Wohnlich 
(loc. cit. p. 32) names as ovary, the albumen 
gland ; and as testicle, the half-canal which runs. 
alung the uterus; but he is in doubt as to the 
function of the hermaphrodite gland. rd, who 
recently gone over the ground, according his views 
with those of Siebold and others above-mentioned 
(see Beitrag, loc. cit. in Siebold and Kélliker’s 
Zeitsch. II. 1850, p. 125, Taf. XIII. fig. 31-48). 
Leydig, however, has watched their formation 
from cells; and here I may remark as being evi- 
dence against their being spermatic particles, that, 
according to him, they are produced by the meta- 
morphosis of an entire nucleolated cell, and not, as 
isthe grand law with spermatic particles, from a 
cell-nucleus. From this and from the above-men- 
tioned reasons, based upon analogy, I cannot ad- 
mit that these peculiar bodies are true spermatic 
particles. Leydig’s observations on their develop— 
ment of course render invalid the hypothesis of 
Gratiolet that they are modified spermatic parti~ 
cles, having undergone changes, like those of the 
Helicina, in the Vesicula copulatrix; see Jour. de 
Conchol. No. I. 1850, p. 116, and No. IIL. p. 
236, PL IX. fig. 3-7.— 
