A REPLY TO HAECKEL 123 



How can Virchow, Ranke, and others, who 

 are not zoologists, in the speeches they annu- 

 ally deliver at anthropological and other con- 

 gresses, continue to declare that this 'Pithe- 

 coid thesis' is an empty hypothesis, an un- 

 proved assertion, and a mere dream of the 

 philosophers of nature? How can these an- 

 thropologists still continue to ask for 'certain 

 proofs' of this thesis when proofs with all 

 the clearness that could be desired lie before 

 them, and are unanimously recognized by all 

 zoologists? As regards Virchow's often 

 quoted declarations against the Pithecoid 

 thesis, they have obtained great favor in wide 

 circles, only because of the high authority 

 this famous naturalist enjoys in an entirely 

 different domain of science. His 'cellular pa.th- 

 ology,' his ingenious application of the cell- 

 theory to the whole province of medicine, 

 introduced a grand advance in that branch of 

 science thirty years ago. This great and last- 

 ing service rendered by him has, however, no 

 connection whatever with the unyielding and 

 negative position which, unfortunately, Vir- 

 chow persists in assuming towards the doc- 

 trine of evolution.'' 



It probably never occurred to Haeckel that 

 the argument which he here uses to meet 

 Virchow's opposition to evolution, would 



