NEW INTERPRETATION OF CNIDARIA 319 



An Attempt to Reconstruct the Initial State of the 

 Eumetazoa 



After all these criticisms, counter-criticisms, and discussions 

 we will now try to reconstruct the initial state or the earliest 

 state of the Eumetazoa. In this attempt I will correct and 

 improve my previous suggestions which were necessarily 

 vague. I am well aware of the hypothetical character of this 

 construction, yet at the same time I believe that it is not 

 simply a product of pure fancy as this has been maintained by 

 some of its critics ; it is based on critically selected facts and it 

 can claim at least some probability, at least as much as can be 

 claimed for those attempts that have been made so far by 

 those who adhere to the colonial theory. It should be discussed 

 critically and compared with the theory which is now generally 

 believed to be true. From the very beginning I have expected 

 that this interpretation would not find an easy acceptance be- 

 cause it requires that the old interpretation which is so deeply 

 rooted and which at the first sight appears so bewitchingly 

 clear should be given up. It cannot be expected that the nume- 

 rous older zoologists could easily relinquish an opinion which 

 they have considered true for such a long time. It is said 

 that such a revolutionary idea will have to wait for the next 

 generation to win its full success. My reconstruction of the 

 origin of the Eumetazoa stands in opposition to the "belief" 

 in the colonial origin of the whole animal world and to a 

 number of other similar "beliefs" (e.g., the question of the 

 relation between ontogeny and phylogeny, the significance 

 of cleavage and of other ontogenetic mechanisms, the idea 

 of germ layers, the "germ path," the general division of the 

 animal world, the problems of the mesoderm and of the 

 coelom, etc.). To this we must add the supposed difficulty 

 which arises because I consider that the Metaphyta and the 

 Spongiae have evolved out of the colonies of Protista, and 

 thus in different ways to that which the evolution of the 

 Eumetazoa had taken. 



