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 Medusse. Will himself does not appear to have dis- 

 covered any particular system of blood-vessels in all Acalephse . . . 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 Acalephse, except the nourishing fluid contained in the abdominal 

 caAdty. Sonie Medusae, however, may possess such. This can be the less objected to a 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 Medusae 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 Stomohraehium, 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 

 Liszia, the condition of the reproductive glands is intermediate between the two modes just 

 described. In Euphysa, the ovary appears to depend from the centre of the peduncular cavity. 



The organs of generation in these Medusse were long misunderstood. Peron and Lesueur 

 recognised their true position in most of their " monostomous gastric Medusse," in which the 

 genera Oceania and Mquorea, 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 Mquorea, however, they did not recognise the ovaries. In their group of " agastric 

 Medusae," of which Geryonia 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 Biscophor^ into 

 Phanerocarpce (exactly equivalent to my Steganopthalmata) and Cryptocarpcs, 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 Medusae, though 



* Frev and Leuckhart. 



