NEW INTERPRETATION OF CNIDARIA 351 



ed from one type, yet not by way of a radiation which had 

 started from the same centre in the same geological age, nor 

 from the same level reached by the primitive type. Such a 

 development can be observed in the Turbellaria as the initial 

 form for the evolution of Ameria with their numerous "side 

 branches" or subtypes. Their developments had probably 

 begun (this cannot be strictly proved) from separate ''Anlagen 

 of buds" (we cannot possibly speak here of roots). 



This shows the relative character of the distinction between 

 the "monophyly" and the "polyphyly." It frequently depends 

 on the taxonomic rank we give to a certain animal group, 

 above all whether this is a phylum in a narrower or broader 

 sense of the word. 



