REPRODUCTIVE SYSTEM. 7 



practically versed in the higher group. Blainville recognised the ovaries in Oceania (following 

 Peron and Lesueur), but mistook them (foUdwing Eschscholtz) for stomachal appendages in 

 Thaumantias, Geryonia, and allied genera. Lesson, confused throughout, repeats the same 

 mistake. Ehrenberg recognised their true position in his " Melicertum campamlatum" (i. e. 

 Stomohrachium octocostatum) and Oceania pileata. Sars first described them in Thaumantias 

 and Stomohrachium as dilatations of the gastro-vascular canals ; but more lately recognised 

 their true office. Milne Edwards demonstrated their true nature in JEquorea violacea, and 

 inferred their office by analogy in all the so-called Cryptocarpee. Brandt appears to have 

 followed Eschscholtz. Will perfectly comprehended their true nature, and demonstrated theii: 

 structure. Fray and Leuckhart take the same view. Indeed, it seems strange that such great 

 diversity of opinion and so much error should ever have prevailed respecting the position of 

 the glands of generation in the naked-eyed Medusae, especially when their true nature in the 

 steganopthalmatous species was recognised by all. 



In Turris, the genus which may be regarded as the highest in organization of the order 

 under consideration, the ovaries are highly developed, and line the upper part or chamber of 

 the stomachal cavity in the form of convoluted tubular and fimbriated membranes, conspicuous 

 from their brilliant colour. Such an arrangement closely approaches that met with in the 

 Steganopthalmata. In Oceania, a similar arrangement, though not so perfectly made out, 

 prevails. In Geryonia, Thaumantias, and allied genera, the ovaries are more or less clavate 

 or leaf-shaped, and are either expanded on the under surface of the sub-umbrella in the course 

 of the gastro-vascular canals, or depend from it as membranous sacs or laminae, the latter form 

 being that seen in Stomohrachium and JEquorea. In Willsia, Bougainvillia, and Li%%ia, 

 they present the appearance of lobes on the sides of the stomach ; but those of the first-named 

 genus are much more regular and normal than those of the two latter. Their number, when 

 well defined, may be very considerable (as in JEquorea and Mesonema) ; but in our British 

 forms the greatest number is that seen in Stomohrachium and Circe, where there are eight ; 

 next, Willsia, which has six ; the remaining genera have four ovaries, each of which, in 

 several instances, is composed of two equal and similar parts. 



Though I have used the word ovaries for these bodies, as if the animals were unisexual, 

 I have done so only as a convenient form of speech. There is every reason to believe that the 

 majority of the Medusae are bisexual, though the two sexes appear to be united, but maintained 

 by distinct organs in certain forms, especially in the higher group. The dioecious character 

 of the naked-eyed forms has been demonstrated by Milne Edwards, Wagner, and Will. The 

 first-named naturalist showed that some individuals of Mquorea violacea were females, having 

 eggs in their generative organs, others on which there were no trace of eggs, but abundance 

 of spermatozoa, being males. 



Will describes the sexual organs of Geryonia pellucida as lying in the course of the 

 radiating gastro-vascular canals, their further extremities rounded, the inner ends pointed. At 

 the latter he found ducts of emission which reach the base of the peduncle. Each gland 

 consists of two lancet-shaped halves ; each half is provided with a special duct of emission, so 

 that there are consequently eight ovaries in the female, and eight testicles in the male, of this 

 genus. " The ovaries are twisted sacs in which the eggs lie close to each other, the largest 

 towards the margin of the disc, the smallest towards the peduncle. The perfectly-developed 

 eggs are of a whitish colour, opake, and measure 1-8'"; the germinal spot is round and 



