DOMAIN OF EVOLUTIONARY HYPOTHESIS 79 



logical methods/ This is certainly that method which 

 adheres to the historical development of the entire 

 evolutional problem, and therefore also that which 

 repeats the original thoughts and permits the newly 

 introduced extensions thereof to be determined. This 

 was the method adopted by an eminent palaeontologist 

 Ch. Deperet in his work so frequently mentioned, 

 and the honourable reception which the book also 

 experienced among German savants l shows that no 

 one found any objection to the plan adopted. 



This, however, does not imply that palaeontology 

 is alone called upon to finally determine the limits of 

 transformation. Thus the possibility of the descent 

 of one plant type from another, despite the perfectly 

 negative results of palaeontology, is by no means dis- 

 proved. In many cases a decision cannot be arrived 

 at by the study of fossils alone because, for instance, 

 the petrifactions of the pre-Cambrian formation even 

 if they existed in larger numbers are in any case 

 shattered or destroyed, and indubitable plant remains 

 are not so far known from pre-Silurian formations. 

 Under these circumstances what can be said regarding 

 the earlier history of the Ferns or the Trilobites ? It 

 will, however, well be conceded that it is inadmissible to 

 speak of and appreciate only the favourable side of the 

 results of palseontological research viz. the abundant 

 evidence in favour of manifold new forms and to be 

 silent regarding the lack of any probable tangible 



1 The book was very favourably spoken of by Freeh, Koken, Steinmann, 

 R. Hoernes and other paleontologists. 



