THE GENESIS OF LIVING ORGANISMS i8i 



be any question of evolution in the old sense ; a real revolu- 

 tion was necessary to bring all the minute parts of organs 

 into reasonable arrangement. 



Haeckel's so-called " biogenetic law " was mainly re- 

 sponsible for giving evolution its last foothold. This law 

 consists in the assertion that in the course of its individual 

 development, every single organism passes through the 

 developmental history of its ancestors, in abbreviated form. 

 Since the history of the ancestors is unknown, it was deduced 

 from the development of the individual, and so was proved 

 by a vicious circle. The vast amount of " literature " that 

 has been written with this fallacy as basis, almost passes 

 belief. And so we may consider it a real feat, when Driesch 

 put an end to the business by demonstrating that in the germ 

 there is no preformed framework for the complete animal. 



The proof adduced by Driesch is just as simple as it is 

 enlightening. The essence of a framework consists in its being 

 made of parts fitted together ; and when one tears it asunder, 

 it is a framework no longer. If there is an invisible frame- 

 work present in the germ, then, when the germ is cut up, the 

 framework must be cut up with it. Now, a halved germ, if it 

 develops further, yields, not two half-animals, but two animals 

 of half the normal size. This fundamental experiment of 

 Driesch 's has been performed with all possible variations, 

 with every possible precaution, and on all suitable species of 

 animals. 



While an anatomical framework must be destroyed by an 

 anatomical interference, since it is expanded in space, a rule, 

 which in its very nature is non-spatial, cannot be severed by 

 the knife. Either the possibility of embodiment is taken 

 from it by destruction of the material, or, if that does not 

 happen, stiU it must come to expression even with reduced 

 material. 



