NEW FACTS. 293 



So little have the facts rejj-istered in the second table been 

 kept in view, that the doctrine of Alternate Generations has 

 been persistently denied on the gTound that the Polyjies are 

 not generations at all — are not, properly speaking, " indivi- 

 duals" any more than leaf-buds are individuals. According 

 to this argument, which has been set forth by Dr Carpenter,* 

 only those can be truly called generations which issue from 

 a generative act, i.e. the union of a germ-cell with a sperm- 

 cell ; an arbitrary assumption disproved by a multitude of 

 facts. He maintains the analogy of the Pol3q)e and the leaf- 

 bud to be complete, and considers the multiplication of 

 Polypes, and of Medusae from Polypes, to be always a process 

 of buddiiig ; this gives his argument a superficial plausibility, 

 which is, however, totally destroyed by the fact that the 

 Polype also produces Polypes by the miion of ova and sper- 

 matozoa. 



I shall have to recur to this point hereafter ; meanwhile I 

 may add that, in the course of a long investigation into the 

 development of the Campanularian and Plunndarian Poljqics 

 — especially P. myriophylluni (Plate IV., fig, 2), from deep 

 water off Jersey — I found that not only does the Polyjie 

 produce Polyjjes by means of ova, but also produces Medusoi 

 in the same way; so that instead of the production of 

 Medusa^- being only one of simple budding, it resembles the 

 production of Polyjjes in being sometimes a process of 

 budding, and sometimes a process of oviparity. I have 

 followed this development through all its stages ; and as 



* Princi2)les of Comparative I'Iiysiolo<jy, 1S54. 



