154 Inadinissibility of Preformistic Germs 
preformistic theories, the absolute inadmissibility of 
which we have seen above. 
ee 
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 
