PRINCIPAL ATTEMPTS AT EXPLANATION 147 



which are adapted so wonderfully to the most varied 

 needs of existence, even to the smallest detail. That 

 is the chief idea, and, in a certain sense, also the greatest 

 service Lamarck rendered : he puts forward a ' theory 

 of organic purposefulness/ not a doctrine of descent, 

 which all problems of the ' history of life ' involve. 1 



With regard to the origin of ' organic purposefulness ' 

 he writes as follows : 



( That, in the first place, any alteration, even incon- 

 siderable, in the circumstances in which each race of 

 animals finds itself, induces an actual change of its 

 requirements. That, in the second place, each alteration 

 in the requirements of the animals renders necessary 

 other faculties in order to satisfy these new requirements 

 and consequently other habits. That thereby each 

 new requirement, since it renders necessary new 

 faculties to meet it, demands from the animal which 

 experiences it either the extended use of an organ of 

 which it had hitherto made less use, whereby such 

 organ is developed and considerably enlarged, or the 

 use of new organs to which the requirements within it 

 imperceptibly give rise through the efforts of its inner 

 perception' (Gefuhl)* 



An example may explain the above : 



1 That we really perceive, in the explanation of the purposefulness of 

 the organisms, the chief merit of Lamarck, is shown in the clearest fashion 

 by the work of the Lamarckian disciples. Thus, for instance, B. M. Pauly 

 says (Darwinismus und Lamarckismus, Munich, 1905, 46) : * His works 

 [L.] contain a theory of organic purposefulness that ... at this moment 

 we have not yet risen above.' 



2 See Dr. A. Wagner : Geschichte des Lamarckismus, Stuttgart, 1909, 

 p. 32. 



L2 



