NEW INTERPRETATION OF CNIDARIA 349 



by the taxonomists. The geologically much older Appendicula- 

 ta, among the Chordoma, were given at least the rank of an or- 

 der. The Chaetognatha, which are considered by some zool- 

 ogists as an extremely isolated group and which are therefore 

 considered to represent a higher systematic category (e.g. Be- 

 klemischew), have even been given the rank of a special class. 

 I have succeeded in showing (Hadzi, 1958 c) that the Chaetog- 

 natha evolved by way of neoteny from some Brachiopoda. 



In connection with the highest animal types, above all in 

 connection with the high systematic category of phyla, it 

 appears as very probable, (1) that there can be only few such 

 categories; (2) that they must be very old taken from a geolog- 

 ical point of view; and, (3) that they evolved as a consequence 

 of a combination of a special genom, the change of the 

 environment, the change in the way of life. 



Finally, I must touch another problem even if I do not 

 consider it to be of a very great importance. This is the 

 question whether the phylogeny of animals had been mono- 

 or poly-phyletic. I wish to mention this problem because 

 some accusations were made against me that, in my attempt 

 to reconstruct the phylogeny, I approach, the pre -Darwinian 

 concepts {'Techelle animale,''^ and other similar interpretations). 

 Quite naturally I must reject such an accusation because it 

 is entirely unjustified. There can be in principle no linear or 

 ladder-like evolution if we accept the standpoint of the neo- 

 Darwinism. The alternative question of a monophyly versus 

 a polyphyly is completely wrong. We can immediately see 

 when we observe all the riches of the animal forms, and above 

 all if we take into consideration also the palaeozoological 

 forms, that the problem can only be of a monophyly and an 

 oligophyly (yet not in an alternative sense). The few attempts 

 to construct a genealogical bush instead of a genealogical 

 tree have not been received favourably by zoologists. Some- 

 thing very similar has been proposed recently by Lemche 

 (1958) who suggested four main branches or subordinate 

 stems. 



