KESULTS OF PAL^ONTOLOGICAL RESEARCH 25 



(d) As regards the origin of the groups already 

 existent in the Cambrian and pre- Cambrian period 

 we shall never know anything certain, not even if other 

 organisms really preceded them, as is demanded as a 

 postulate by the extreme evolutionary hypotheses. 1 



In the meantime is the pre- Cambrian or Cambrian 

 fauna to be scientifically regarded as the real original 

 fauna ? The groups already existing show, in many 

 representatives, about the medium height of organiza- 

 tion of the animals of the present day. Of a fauna 

 in its entirety, of a lower grade and still older, there 

 have been in any case no remains discovered (see c). 

 If such really existed we should hardly ever be likely 

 to learn something from it (see d), since the formations 

 which are older than the pre-Cambrian nay, even 

 these themselves for the greater part are throughout 

 so greatly metamorphosed that all and any fossils 

 which they might have contained would be destroyed. 



(2) The form of animal life in the post-Cambrian 

 formations. 



The justification for uniting several sedimentary 

 formations in a single group (formation, e.g. Silurian, 

 Devonian, etc.) is found in certain peculiarities which 

 we see recur in the history of organic life in what 



1 Deperet-Wegner : Die UmUldung der Tierwelt, p. 312. ' From these 

 facts should it be concluded that we must for ever desist from hoping to 

 solve a problem so passionately discussed as that of the commencement 

 of life on the earth, or at least to be able to follow it further back ? 

 Unhappily it must be granted that that is the most probable prospect 

 before us.' (This remark shows also that a so highly developed fauna was 

 not anticipated.) 



