96 Messrs. Hancock and Enibleton on the Anatomy o/Eolis. 
bear a good deal of resemblance to those of the other Nudi- 
branchiata as described by Cuvier ; but in assigning the peculiar 
functions of the various parts, we differ from that distinguished 
physiologist. It is however only after often-repeated careful dis- 
section, observation and deliberate consideration that we venture 
to dissent from such high authority, and we feel it incumbent 
upon us to state generally in what points we differ, and the reasons 
of our dissent. 
That part in Doris called by Cuvier testis answers to what we 
call the mucus-gland : that it is not testis we are assured, by its 
having no direct connexion with the male parts, but opens very 
evidently into the female channel, of which it is an appendage ; 
we have several times examined its secretion, and found it to cor- 
respond exactly with the mucus-like matter that envelopes the 
ova. Again, the convoluted tube, called by Cuvier penis, we be- 
lieve to be the testis, and for the following reasons : — 1st. It is 
not uncommon to find the true penis, exserted in specimens pre- 
served in spirits : on examination of the parts of E. papillosa in 
such case, the penis of Cuvier is still found in the interior of the 
body as a closely convoluted tube, the coils of which are nearly 
all attached to each other by fine filaments, as noticed in our de- 
scription, and are therefore not susceptible of being unrolled and 
made to act as an intromittent organ. A small portion however 
is freer than the rest, and is often found at the base of the penis, 
being prolonged also to its extremity as the excretory duct of the 
testis. 2ndly. Its internal structure and its contents are clearly 
those of a glandular organ, and spermatozoa have been found in 
it in E. coronata ; and lastly, its connexions as already pointed 
out, namely with the penis at one end and with the oviduct at 
the other, seem to indicate pretty accurately its character. 
The sac we have called spermatheca we have ventured so to 
name, because we find it possesses a channel of communication 
with the exterior and a direct connexion with the oviduct, besides 
containing, as we have witnessed in E. papillosa and E. coronata, 
abundant masses of densely packed spermatozoa. This organ is 
doubtless the ^^vessie” of Cuvier. 
In passing from the Barones description of the genitalia of 
Doris, while we are glad to acknowledge that his plates and de- 
scriptions have been of great service to us in confirming in many 
points the result of our own dissections, we cannot help being sur- 
prised that two other anatomists, who have so recently been en- 
gaged upon the corresponding organs of some of the Eolididee, 
have not availed themselves of the store of valuable information 
accumulated by their illustrious precursor in the same path of in- 
vestigation in his ^ Memoires pour servir ’ &c. — we allude to 
MM. de Quatrefages and de Nordmann. If we turn to the former 
