THE NEW GENEALOGICAL TREE 453 



Remane as well as all the other attempts to derive bilateral 

 symmetry from a radial symmetry with the "Coelenterata" 

 as the initial form of this evolution, and above all the attempts 

 to derive by means of the enterocoelic theory, a trimetamerism 

 from the gastral diverticula of a tetraradial polyp of the Cnida- 

 ria. At the same time he wishes to preserve the division of the 

 Eumetazoa into the Protostomia and the Deuterostomia, and 

 in this respect he goes so far that he tries to place this un- 

 fortunate bifurcation back into the "gastraea" stage (he com- 

 pletely disregards here the Spongiae as well as the Cnidaria 

 and the Ctenophora). Steiner has made here, I think, two 

 basic mistakes ; first, when he describes the youngest Metazoa 

 as animals that live in plankton, and, secondly, when he 

 interprets the larval forms as representatives of their adult 

 ancestors. Steiner took great pains to make probable the 

 early bifurcation of the two lines of evolution ; the Protostomia 

 and the Deuterostomia, and to provide this thesis with a 

 solid foundation. This attempt, however, must be consider- 

 ed as completely unsuccessful, similarly as has also been the 

 case with a not very different attempt made by Boettger. 

 His construction, the Neurenterica, is, I think, unable to 

 live. 



Even the apparently fortunately suggested line of evolution, 

 plankton— benthos— nekton is unable to stand an objective 

 analysis. The benthos represents the starting point and the 

 main type of life from which both plankton and nekton 

 evolved. 



It is also wrong to use the ecotypes, even as an auxiliary 

 method, in high taxonomy. All the main types of life (of 

 feeding), e.g. the predatores, turbellores, and the fossores 

 (according to Steiner), can be found as early as in the Protozoa 

 (the numerous benthonic Rhizopoda are fossores). In the 

 Metazoa they do not follow each other in the w^ay sug- 

 gested by Steiner. We can find in the Cnidaria all these types 

 of life represented perhaps with the exception of the burrow- 

 ing animals (ceriantharia) if we do not wish to consider as 

 30 



