228 Theories Treating of Inheritance 



formation of a few new nerve paths, at the same time 

 reproduce those parts of the organism which remained 

 entirely unaffected by this local change ? 



Finally, how can the hypothesis of Spencer account 

 for the law of repetition of phylogeny by ontogeny? If 

 the explanation of the inheritance of acquired characters 

 by means of physiological units were accepted, this law 

 would be futile. For the new physiologic units with 

 changed polarity must take on at once in the daughter 

 organism that form to which the parent organism had 

 last attained, without needing to pass first through the 

 preceding forms. 



The physiologic units were devised in order to permit 

 the comparison of the formation of the organism with 

 that of a crystal. But a substance which because of a 

 slight qualitative alteration of its molecules changes its 

 form of crystallization, goes over from the very first 

 commencement of crystallization into a form different 

 from the preceding, and takes on at once the form which 

 it will have after the completion of crystallization. A 

 comparison between organisms and crystals is therefore 

 inadmissible; and this inability is especially evident when 

 it is attempted in this way to explain the laws and 

 phenomena of development, in which organisms and 

 crystals are totally different and are even antagonistic. 



Haacke 



The conception of Haacke is much like that of 

 Spencer. 



"According to my view/' says he, "we have to do not 

 only with the genetic continuity of the germ cells of one 

 generation with those of the generation immediately pre- 

 ceding and following, but also with a material continuity 



