382 THE EVOLUTION OF THE META2^0A 



cephalization, and which possessed a ventral opening and even 

 an anal opening and in all probability also protonephridia. We 

 think that in this way too many requisites have been given 

 to this hypothetical initial form. This can be seen above all 

 when we try to derive the aproctous Platyhelminthes from it, 

 while on the other hand it is not difficult to derive the 

 Coelenterata from it because we can rightly maintain that some 

 of these requisites had been lost due to the transition of these 

 animals to a sessile way of life. As regards the Platyhelminthes, 

 Carter must make some revisions ; he must derive them from 

 an even older primarily aproctous primitive form in which 

 case he will be obliged to consider the Platyhelminthes as an 

 independent branch— thus as the fourth branch— or he should 

 go back to an already disqualified interpretation and consider 

 the aproctous state as a secondary phenomenon, as a con- 

 sequence of a degeneration. 



We can easily understand that Carter does not assume a 

 strictly negative attitude towards my interpretation. Carter 

 discussed my suggestions twice. The first time in a very 

 objective report which appeared in the review Science 

 Progress; in this report he gives very adroitly all the essential 

 points of my construction. Carter stresses judiciously that 

 "it is not likely that zoologists will soon reach general agree- 

 ment on them" (sc. my interpretations in the field of the 

 "high phylogeny"). He mentions correctly the great interest 

 which exists about these problems, and states as follows, "It 

 is refreshing to read a discussion of these questions in which 

 the results of recent zoology are taken into account. For this 

 we have to thank Prof. Hadzi." 



In another detailed study (Carter, 1954) Carter took 

 a critical attitude towards my suggestions as they appeared 

 in the article which was published in Systematic Zoology. In this 

 study Carter accepted, at least partly, my interpretations and 

 expressed his opinion that it could be expected that my inter- 

 pretations would not be accepted by many zoologists. Un- 

 fortunately enough Carter could not come to any conclusion 



