THE FISSIGEMMATION OF AURELTA. 



67 



diverse extremes of the generation of one individual. 



other until they finally meet, (fig. 33,) just as the two individ- 

 uals separate. These two resultants of the operation which has 

 just been described, are to all intents and purposes perfectly 

 identical in their organization, the only difference being that 

 one is, in part, older than the other. 



Now, as I have said before, there are all possible gradations 

 between the methods of reproduction by budding and those by 

 development from the egg ; and I intend next to illustrate the 

 first step tending toward the latter process, although it is very far 

 off" from it. The resultants of the process, which is one of self- 

 division, are unlike each other, and on this account the term 

 alternate generation has been applied to this, along with other 

 allied forms of reproduction. 



I will introduce at once the two forms which represent the 



You 



would not suspect by their figure (figs. 34, 35, 

 and 36) that they were in the least related to 

 each other ; but yet the method by which the 

 one is transformed into the other is perfectly 

 pimple. The Hydra-like individual, (figs. 34, 

 35,) with its short, trumpet- 

 shaped body, and long, wavy, 

 hair-like tentacles (), was form- 

 erly believed to be a sort of ma- 

 rine Hydra, and received the 

 name of Scyphostoma ; and al- 

 though it is now well known to 

 be one of the stages of growth of 

 the Sunfish, yet it goes by the 

 name of, or is spoken of, as the 



Fig. 34. The Scyphostoma of Aurelia 'flavidula. Per. and Les. Natural 

 size, a, the base, attached to the side of the aquarium; /, the tentacles hanging 

 looselv, at their fullest extension, and waving to and fro with the movements of 

 the water. Original. 



Fig. 35. The same as fig. 34, magnified eight diameters, a, the base ; m, the 

 partially extended proboscis encompassed by the tentacles t ; </, the incipient for- 

 mation of the Ephyras, foreshadowed by transverse rings. Original. 



Fig. 34. 



