6 REPRODUCTIVE SYSTEM. 
entirely correspondent with ours, was likewise obtained by our respected friend Professor 
Bergmann, during numerous observations which he had an opportunity of instituting, during 
a residence at Iceland, on many different Medusze. Will himself does not appear to have dis- 
covered any particular system of blood-vessels in all Acalephe . . . We believe ourselves justified 
in pronouncing an opposite opinion, viz., that no special blood-fluid, or any special vascular 
system, exists in many of the Acalephz, except the nourishing fluid contained in the abdominal 
cavity. Some Medusz, however, may possess such. This can be the less objected to @ priori, 
since we know that the development of the vascular system in the different classes is subject to 
very considerable differences. The statements of Will are moreover, in many respects, too 
decided, as not to allow us altogether to doubt the correctness of his observations, although it is 
the very peculiar behaviour of the blood-vessels, as described by him, which justifies us in 
believing in the possibility of an error; in addition to which, we must mention that our own as 
well as Bergmann’s observations have furnished quite a different result from those of Will. 
Indeed the question can only be decided by new and careful observations.”* 
With these judicious remarks I entirely agree, and hope the suggestion of further inquiry 
will be taken up by some of our expert microscopical observers, qualified for such an inquiry 
by possessing the requisite physiological knowledge, without which microscopical researches 
must always, and justly, be received with distrust. 
Reproductive System.—The majority of the naked-eyed Medusze have very distinct 
reproductive glands. These are placed either on the surface of the sub-umbrella, or on the 
inner and upper part of the peduncular cavity. In each case their position has a distinct 
relation to the arrangements of the gastro-vascular canals. Instances of the former 
arrangement are seen in Stomobrachium, Geryonia, Thaumantias, Circe, and Slabberia ; 
of the latter, in Turris, Saphenia, Oceania, and Willsia. They are not so definitely marked 
in Sarsia, Steenstrupia, and Modeeria, in which genera the whole of the substance of the walls 
of the peduncle seems to be composed of a germ-producing tissue. In Bougainvillia and 
Lizzia, the condition of the reproductive glands is intermediate between the two modes just 
described. In Huphysa, the ovary appears to depend from the centre of the peduncular cavity. 
The organs of generation in these Medusz were long misunderstood. Peron and Lesueur 
recognised their true position in most of their “monostomous gastric Meduse,” in which the 
genera Oceania and Aiquorea, according to their view of the extent of those groups, were 
placed along with Pelagia, and other forms having no true immediate affinity. In the case 
of AZquorea, however, they did not recognise the ovaries. In their group of “ agastric 
Medusze,” of which Geryonza may be cited, they seem altogether to have misunderstood these 
organs. ‘Their importance and meaning were equally lost sight of by Lamarck. Eschscholtz 
still further lost the clue to their signification ; for, founding his system upon the supposed 
manifestation or obscurity of the reproductive glands, he divided all the Discophore into 
Phanerocarpe (exactly equivalent to my Steganopthalmata) and Cryptocarpe, the latter 
group including the naked-eyed forms, describing the generative organs in the latter as 
stomachs or appendages of the stomach. Cuvier, misled probably by Peron, does not seem to 
have clearly comprehended the signification of the parts in this section of the Meduse, though 
* Frey and Leuckhart. 
