cases in which an attempt has been made to bring the de- 

 scent-system into agreement with the actual facts, the in- 

 congruity between the two has become obvious." Thus, 

 for instance, the well-known archaeopteryx is not, as was 

 maintained, a connecting link between reptile and bird, but 

 a member of a blindly ending side branch. In fact palaeon- 

 tological research has proven incapable of finding the tran- 

 sitions between different species, clearly determined by the 

 theory. But the overwhelming abundance of matter called 

 for new endeavors to master it. It was then further 

 discovered — Steinmann finds an illustration of this fact 

 in the echinodermata — that the well-known "fundamental 

 law of biogenesis" of Haeckel can be accepted only in a 

 very restricted sense and may even lead to conclusions ab- 

 solutely false. We desire to remark here that a ''fundamen- 

 tal principle" should never mislead; if it does so, it is not 

 a fundamental principle. 



It is of importance to know that according to palaeon- 

 tological investigation, empiric systematizing and phyloge- 

 netic classification do not always coincide, as, for instance, 

 in the case of the ammonites. Acording to palaeontological 

 investigation the great systematic categories are only 

 grades of organization. Hence present day systematizing 

 is being more and more discarded, and the said categories 

 — as indeed also the lesser groups of forms — must be of 

 polyphyletic origin, that is, they must have descended from 

 different primitive stocks. It may be asked: What bearing 

 has this principle of multiple origins? For a long time rep- 

 tiles were the predominating vertebrates; when mammals 



63 



