154 Inadmissibility of Preformistic Germs 



preformistic theories, the absolute inadmissibility of 

 which we have seen above. 



* * * 



What conclusion can be drawn from the last two sec- 

 tions of the present chapter ? 



The penultimate section has shown us that the actual 

 independence in variation and inheritance of the various 

 and particular characters of all the rest of the organism 

 can be explained neither by a homogeneous germ sub- 

 stance, nor by a heterogeneous germ substance of which 

 all the various constituents would become active from the 

 first moment of development. The last section has dem- 

 onstrated to us the inadmissibility of preformistic germs 

 although at first they appear to constitute the most im- 

 mediate explanation of the mutual independence of the 

 various particular characters. 



It remains then for us to see if a heterogeneous germ 

 substance without preformistic germs, but whose con- 

 stituent parts instead of entering all into action from the 

 first moment of development, become active successively 

 from the commencement to the end of development, can 

 give the adequate explanation of particulate inheritance 

 which we are seeking. 



Let us consider first the phenomena of particulate 

 inheritance which are shown by the presence in the child 

 of certain paternal characters simultaneously with other 

 maternal characters, intermingled but yet clearly distin- 

 guishable from one another. For the sake of clearness 

 we shall overlook for the moment all sexual peculiarities 

 and limit ourselves to considering only the clearly asexual 

 paternal and maternal characters. "The form of the 

 skull," remarks Weismann for instance, "can be paternal 

 and the face maternal; the form of the entire head and 



