NEW INTERPRETATION OF CNIDARIA 313 



The quicker and higher development of the Eumetazoa was 

 made possible by their animal type of feeding which is con- 

 nected with a search for the living prey, and by the free mobi- 

 lity which is connected with their type of feeding, and finally 

 by the direct transference to the Eumetazoa (of the type of 

 Turbellaria) of an already plasmodial and polykaryonic unit 

 which had already been enriched by all those elements that 

 could be attained in a monocellular state. It has already been 

 repeatedly stressed that quite a few zoologists already before 

 me had taken into consideration the possibility that the Metazoa 

 had evolved from some infusoria-like ancestors. Yet they were 

 unable to develop a clear concept because they stood under 

 the influence of the now still widely accepted interpretation that 

 the Spongiae, the Cnidaria, and the Ctenophora, thus the 

 so-called Coelenterata, are the lowest Metazoa (we will bypass 

 the Mesozoa which are still very problematic). The only 

 thing these scholars dared to do was make a few brief and 

 vague remarks on the subject. The way to the new inter- 

 pretation has become open only now after we have first 

 developed a new concept of the evolution of the Cnidaria, 

 after an exclusion of the Spongiae from the sphere of Eumeta- 

 zoa, and after a removal of Ctenophora from a society with 

 Cnidaria, and finally after we have bypassed the so-called 

 Mesozoa. To this wt must also add the recognition that the 

 Acoela have the lowest organization that can be found among 

 the Turbellaria, and that this simplicity is not a consequence 

 of an eventual retrogression but rather a primary phenomenon. 

 The situation became clear when the barrier that had arti- 

 ficially separated the polykaryonic and therefore plasmodial 

 Infusoria from the equally plasmodial and polynuclear Acoela 

 was dropped. 



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