310 SEA-SIDE STUDIES. 



7. The Polype produces Polypes hy ova directly, i. e. 

 without going through the Medusoid generation. 



Attention is called to this second series, because the 

 facts therein registered have been too often lost sight of 

 in the discussion of the theory. AMien, for example, so 

 much stress is laid on the analogy between the develop- 

 ment of a Polype into a Medusa, with that of a bud into 

 a flower, it is apparently forgotten that, in spite of the 

 resemblances, great differences are discoverable. No 

 flower produces similar flowers by a process of budding, 

 as the Medusa buds off young ]\Iedus8e from its sub- 

 stance : a rose does not split up into a dozen roses. 

 ■ So little have the facts registered in the second table 

 been kept in view, that the doctrine of Alternate 

 Generations has been persistently denied on the ground 

 that the Polypes are not generations at all — are not, 

 properly S23eaking, "individuals'' 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 mth a 

 sperm-cell ; an arbitrary assumption disproved by a 

 multitude of facts. He maintains the analogy of the 

 Polype and the leaf-bud to be complete, and considers 

 the multiplication of Polypes, and of Medusae from 

 Polypes, to be alvv'ays a process of budding ; this gives 

 his argument a superficial plausibility, which is, how- 

 ever, totally destroyed by the fact that the Poly]3e also 

 produces Polypes by the union of ova and spermatozoa. 



* Principles of Comparative Physiology, 1854. 



