DEVELOPMENT. 



S3 



their history after detachment from the parent-medusa are still wanting, in order to enable us to 

 speak positively on this point. 



In certain medusae belonging to the family of the Gcryonida it would seem, from the 

 observations of Gegenbaur,' Kollikcr," Krohn,'' Fr. Miiller,'' Keferstein and Ehlcrs,'^ and, above all, 

 from the remarkable researches of Haeckel," that the formation of buds within the cavity of the 

 stomach is a constant and normal phenomenon. It would further appear that these buds, for the 

 most part, detach themselves while still in a very immature state, and that after becoming free 

 they undergo a metamorphosis before arriving at their adult condition ; and, still further, it has 

 been shown that in at least some of these cases there is a hcteromorphisni, the b\ids becoming 

 developed into a form very different from that of the medusa which gave rise to them. 



Fig. 37. 



Fig. 38. 



Sarsia, captured in tlie open sea, with 

 medusa-buds borne by tbe manu- 

 brium. 



a, Wide oral extremity of the manu- 

 brium; b, b, attenuated proximal por- 

 tion of the manubrium, carrying the 

 buds in various stages of development. 



Medusa, probably the planoblast of a Sifncorynet captured 

 in tbe open sea, and bearing clusters of medusa-buds on 

 the bulbous b;ises of the marginal tentacles. 



This last phenomenon has been witnessed in a case recorded by Fritz Miillcr,' who describes 

 the formation of cihated buds from the internal surface of the stomach in an eight-tentacled 

 Cunina, which he names C. Kollikcri. He traced these buds through various stages until he 



' ' Generationswechsel/ p. 56. " ' Zeit. f. wisscn. Zool.' 1843, p. 327. 



^ 'Archiv, fur Naturgesch.' 18G1, p. 1G8. * Thid., p. 51. 



^ ' Zoologische Beitrage/ 1861. 



^ 'Die Familie der lliisselquallen (Geryonida)/ 1865, p. 115, &c. 



^ ' Wiegmann's Archiv/ 1861. 



