COBBOLD, 0.\ yVRODACTYLUS ELEGANS. 37 



One of the most stnkiug plienomeua connected with the 

 reproductive process^ is the remarkable size of the young at 

 the time of birth. In the instance just given I carefully 

 compared parent and child^ but^ in regard to size, I can 

 scarcely aver that the former was the larger of the two. The 

 similarity of bulk is, perhaps, more apparent than real, owing 

 to the circumstance that tlie freed embryo rapidly extends 

 itself, and moves about in all directions, whilst the parent 

 as readily contracts, or " shuts up,^' so as to appear at a 

 striking disadvantage. 



In a second young individual I particularly remarked the 

 curious changes affecting the skin, which Wagener describes 

 as occuri-ing ^'^ shortly after the birtb of an embryo'^ (loc. 

 cit., p. 198). The integument was here and there thrown 

 into villous-like projections, which, as Wagener implies, in- 

 volved the subcutaneous tissues. There was a degree of 

 regularity in their disposition, and their general aspect 

 forcibly reminded me of the permanent, compound, wart- 

 like processes or spherules seen on the surface of Sphceru- 

 lariu. 



In regard to the disposition of the hooks on the caudal 

 disc, as well as other arrangements connected with the in- 

 ternal anatomy, I have nothing new to add ; but, so far as 

 my examinations have extended, I have satisfied myself as 

 to the general accuracy of Dr. Guido Wagener's elaborate 

 descriptions ; and I have thought it might not be unaccept- 

 able to append Professor Wedl's conclusions, as given in 

 his '^ AnJiang liber die Gattuny GyrodachjJus,'^ at the close of 

 the memoir previously referred to. 



I must premise, however, that in this same memoir he 

 makes the following statement : '' During my inquiries," 

 he says, '' respecting the genus, the species (named) Gyro- 

 dactylus elecjans never turned up; on the contrary, I met 

 Avitli numerous forms attached to the fresh- water fishes, which 

 materially circumscribe the universality of SiebokVs inference 

 that Gyrndactylus is only a kind of nurse." 



Dr. Wedl's conclusions are afterwards recorded as follows : 



"I. As hitherto known, Gyrodactylus is found on the 

 gills ( G. ehgans being also found by Creplin and Siebold on 

 the fins) of fresh- water fishes in numerous forms, and as, 

 moreover, I have found a particular gyrodactyle-representative 

 on nearly every species of such fish, it would appear that each 

 finny creature supplies its own Gyrodactylus. Sometimes 

 two of them play the parasite upon the same gill, and they 

 are frequently associated with TrichodinxB, as well as Avith the 

 still unintelligible Psorospermice. 



