106 THE EVOLUTION OF THE METAZOA 



Its solitary state is probably a secondary phenomenon, deve- 

 loped out of living in cormi, a fact which seems to be suppor- 

 ted by its budding which exists to a slight degree only and 

 which no longer leads to the formation of a colony. The 

 main element of the asexual reproduction, or, rather, multi- 

 plication, is a transfission with a simultaneous transmission 

 of the sexual function to the freely living (not freely moving !) 

 generation. It is clear that such a situation must be considered 

 as a special "invention" made by Fungia. Yet it nevertheless 

 represents an element of the formation of medusae— all this 

 in the sense of Watson's mosaic theory. 



It seems much more probable, even if we do not take into 

 consideration the basic problem of the origin of the Anthozoa, 

 that there is no primary medusa form in Anthozoa. If we com- 

 bine this with the conclusion that in the Anthozoa the inter- 

 nal bilateral symmetry is a primary property, we come to the 

 more probable conclusion that the Anthozoa are the most pri- 

 mitive Cnidaria. In case one would like to stick to the old 

 "beUef " in the primitiveness of the Hydrozoa, it would be 

 necessary to take refuge in the comfortable supposition 

 that the Anthozoa had been separated very early from an in- 

 different ancestor of the Cnidaria. This auxiliary solution, how- 

 ever, is improbable and it does not offer a rational expla- 

 nation. 



The Primarily Solitary Polyps Appear 

 in Anthozoa Only 



The next piece of evidence of the primitiveness of the 

 Anthozoa is the fact that it is in the Anthozoa only that the 

 primarily solitary species can with certainty be found. So far, 

 too little significance has been attributed to this fact, or it has 

 not even been taken into consideration. Everywhere, in all 

 the three classes of Cnidaria, solitary species have been found 

 (here the polyp form can only be considered!), and they all 

 have usually been thought of as primarily solitary species. 



