378 DB. ALLMAN ON THE ANATOMY AND PHYSIOLOGY OF CORDYLOPHORA. 
disc nor stomach presents any obvious opening in the capsules of the pohje, but 
this is merely a particular and non-essential modification of structure adapted o the 
function which more especially devolves on them, and it must be recollected tha^ 
being in direct communication with the common cavity of the parent stem thei 
L no need of the admission of nutritive matter from without. >either do^s e 
ramified condition of the tubes, nor the absence of the marginal canal, invalidate the 
view here taken, for we know that the gastro-vascular canals in certain true Medu 
are ramified, while the closed condition of the disc brings with it the absence of he 
“ lte“re’irrrfficulty in the determination of the exact part of the reproductive 
ca sides, which is immediately concerned in the production of the ova or sperma- 
tozoa. As soon as ever these bodies become apparent they are seen to occupy th 
entire space between the diverticulum and the walls of the inner vesicle. The ob- 
servation already mentioned, as made by Duiaroin on a Syncoryne in whose free 
medusoid the ova were produced in the substance of the stomach-walls, would render 
it probable that in Cardylophora also they had their origin in the part homologous, 
nlmly 1 central diverticulum, and that from this they became liberated at a very 
early Le to undergo subsequent development in the cavity of the capsule; and this 
“ew is further supported by what I have myself observed in the fixed egg-bearmg 
organs of Sertularia argentea, to be presently referred to. 
With the reproductive capsules of Cordylophora we may now compare fixed 
ovigerous sacs of the marine genera. It will be seen that these also possess a tru 
meLsoid structure, though this is perhaps not quite so easily made out in eiT. y case 
as in Cordylophora. In the marine Tabulariadw, the sacs in question consist of 
closed vesicle composed of cells, and surrounded externally by a delicate struc ure- 
tZZsl; into its bottom projects a large, hollow, cylindrical and contraCil 
organ, whose cavity is in connection with that of the supporting P«'ype, a»d rou d 
which the ova are developed. Now this central organ corresponds exactly 
central diverticulum in the reproductive capsules of Cordylophora, and plainly lepi - 
sents the proboscidiform stomach of a Medusa, while the cel ular sac is » 
with the disc It is true there is nothing here which evidently represents the gastro- 
vascular canals of the Medusre and the ramified tubes in the capsules of 
but there is vet quite sufficient essential resemblance to justify us iii lefeir „ 
Sr due ive “capsules of the marine Tululariadoe to the type of medusoid struc u e, 
,riich we have just seen that those of Cordylophora admit of a close coinpansoii. 
In the Campanularice, besides the bodies of obvious medusoid stimcture which ha c 
beL noticed by so many observers to escape from the capsule and then Mviin fr ely 
away, and thosi of less completely developed, though still obvious medusoid structme 
which remain attached at the mouth of the capsule, others are commonly seen in .h,. 
. The medusoids of the marioe nhul.nai. are, during the early stages of their development, eon. dned in 
a deheate external sao which afterwards disappears. This is the homologne of the external mvestmen. 
reproductive capsules of Cordylophora and the marine Tubulariadce. 
