342 THE EVOLUTION OF THE META20A 



Stage, that there are some closer phyletic connections, will 

 come in all probability to the wrong interpretation of the 

 phylogenetic developments. This is the case with the inter- 

 pretation proposed by Marcus (1958) regarding the Ectoprocta 

 and Endoprocta. He tries to unite these two groups because 

 of an accidental similarity that can be observed in their larvae 

 (the trochophoroid larvae) in spite of the great difference which 

 actually exists between these two animal groups, especially 

 as regards the organization of their adult forms. These are 

 clearly analogies only that occur in the adult forms and in 

 larvae (cf Had^i, 1958 and P. Brien, 1960). 



The more probable interpretation seems to be that special 

 larval stages were developed independently by each larger 

 group of animals. The way of life of these larval stages is 

 completely different from that of the adult animals. We can 

 come to a more plausible conclusion regarding the relation- 

 ship connection only if we also take into consideration other 

 very important characteristics and peculiarities which are not 

 limited exclusively to the larval stage. 



Fortunately enough we find that recently zoologists have 

 become more and more convinced that it is necessary to 

 relinquish the erroneous "fundamental biogenetic law" which 

 sees whole phylogenies repeated in the ontogenies, with a 

 very small number of deviations (^'Falsch/mge^'') which cover 

 10-0 per cent only of the total number ; all the rest are, accord- 

 ing to this interpretation, palingeneses, i.e. recapitulations. 

 We get such an impression when we read the reports (both 

 reviews and discussions) given at a special symposium of 

 zoologists from Northern Germany, Ontogenie itnd Phjlogenie 

 (Zoo I. A^f^., 164, 1960). On the other hand we find scholars 

 who still adhere to this quasi-law^ and who try to save w^hat 

 can still be saved (Remane and his school). They courage- 

 ously defend Haeckel's definition, making only occasional 

 retreats, while at the same time they miss the main point which 

 is that this old concept is \\rong in principle when it compares 

 the ontogenetic stages of recent animals with the adult 



