SUGGESTIONS FOR RELIABLE HYPOTHESES 179 



From this agreement between construction and 

 needs on the one side, and the mode of existence 

 on the other, there follows nothing in support of any 

 evolution whatever, since adaptability to purpose 

 and this agreement is nothing else is a general 

 phenomenon throughout the whole organic world : all 

 animals and plants possess those organs and capacities 

 (i.e. arrangements in plants) required to fit them exactly 

 for existence in their habitats or resorts, and to enter 

 into or be brought into relations with those objects or 

 organisms which are necessary for the maintenance of 

 life and of reproduction. 



The closer observation of the Parasites affords, 

 however, several very important points in support of the 

 assumption that their mode of existence, and conse- 

 quently their construction and their physiological 

 constitution (as means to an end), are something 

 subsequently acquired (secondary) and not of primary 

 origin ; or, expressed in the language of the time, the 

 present form of the Parasites in the adult stage, and 

 many peculiarities of the embryological genesis, present 

 the result of a transforming (evolutionary) process 

 they are ' adaptations/ If that be really the case 

 then certainly the transition to the parasitical mode of 

 life has been the cause of the production of the most 

 manifold forms of animals and plants, which often 

 enough we can only bring into our ' system ' with 

 great difficulty. 



' Adaptation ' (Anpassung) therefore does not imply 

 every agreement between construction and function. 



