196 MR. À. HANCOCK ON THE ANATOMY OF DORIDOPSIS. 
well-marked structure was fully determined and figured in the * Monograph of the British 
Nudibranchs ' *. : 
The structure of the ovary in Eolis papillosa is very similar to that in Scyllea, 
Each lobe of the organ represents one of the globular masses of the latter, and is pene. 
trated by a branch of the oviduct (fig. 11c), which passes up the centre of the lobe, 
giving off lateral branches, which, dividing and subdividing, radiate towards the cir. 
cumference and communicate with the inner extremities of various systems of two or 
more elongated fusiform vesicles (7), the outer extremities of which are, for the most 
part, bifid, and terminate in one or more ovigerous sacculi (e); these, however, are not 
marked off by any constriction (fig. 12). The vesicles themselves, or the inner portions 
of them, produce spermatozoa. Thus it may almost be said that, in this form, the 
male and female elements are secreted by different portions of the same vesicles or 
sacculi. | 
From the above-cited examples, there can be little doubt that in the whole of the Nu- 
dibranchs the so-called ovary is a compound organ, producing both the male and female 
elements, each being secreted by a definite part of the organ, most frequently in distinct 
sacculi or vesicles, though the male vesicles occasionally assume the form of ramified 
tubes. Such being the case, it might safely be concluded that this organ is also com- 
pound in Doridopsis, even though the details had not been at all determined; enough, 
however, has been observed to warrant the belief, after the above examination, that 
the ova and spermatozoa are developed in distinct sacculi or vesicles. 
The oviduct in this form ramifies, as a minute tube, throughout the so-called ovary, 
which is composed of a vast number of small lobules, each of which is formed bya 
cluster of pyriform ovigerous sacs. A delicate branch of the oviduct penetrates into the 
centre of each lobule, and distributes radiating twigs to the inner or small extremities of 
the ovigerous sacs. The twigs are considerably dilated as they reach the sacs, and form 
apparently the male sacculi. Thus it is sufficiently clear that the so-called ovary im 
Doridopsis is a compound organ secreting both the male and female elements, as it does 
in all the other Nudibranchs referred to. But neither in it nor in the latter is there the 
slightest indication of the invagination of the testicular sacculi within the ovarian, a8 
stated to be the case by Heinrich Meckel T; nor does it appear that the vas deferens 
is included within the oviduct, as asserted by the same authority. Indeed there -— be 
no doubt that in the Nudibranchs, at least, the oviduct is a simple tube, and that it acts 
first in the capacity of a vas deferens and then as an oviduct. In the one case - 
spermatozoa will be conveyed by it to the glandular tube connected with the penis, which 
tube is the vas deferens proper; in the other case the ova will pass down the oviduct 
into the mucous gland, and so to the female outlet. | 
The enormous extent of the glandular tube or vas deferens proper is, nevertheless, P" 
extraordinary, partieularly in some of the Dorides, as, for instance, in Doris tuber ge 
- Terany, in which not only is the attenuated portion of great length, but the p? 
which corresponds to the dilated division in Doridopsis assumes the form of à bulky 
* See Fam. 2, plate 5. fig. 7 of that work. 
T See Report on Zoology for 1844, published by the Ray Society. 
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