Driesch 243 
tainly do not denote any endeavor of the idioplasmic 
substance to proceed by the shortest route to the condi- 
tion of its equilibrium. They indicate that it is quite 
impossible on the one hand to accept the passage of 
ontogenetic through phylogenetic forms and on the other 
hand to refuse to this process the significance of an actual 
repetition of phylogeny by ontogeny. In other words 
one must seek the cause of this repetition not merely in 
biologic laws of maintenance of the equilibrium in an 
existing homogeneous idioplasm, but chiefly in the entire 
past of the species and just in the historic fact that it 
passed during its development through such and such 
phylogenetic forms. 
And so the objection urged by Weismann against 
Nageli can be urged in its full force and even more justly 
against Hertwig. For though Nageli gave no explana- 
tion of their causes and ways of action, he nevertheless 
accepted the activation of a whole series of different 
anlagen of the idioplasm in exactly the same serial order 
as in their phylogenetic appearance. Hertwig on the con- 
trary after he had first accepted this activation of succes- 
sive anlagen of the idioplasm finally rejected it. 
Driesch 
This author’s conception of organic development 
cannot in its very nature afford any explanation whatever 
of the inheritance of acquired characters and conse- 
quently, admitting that this inheritance exists, ought for 
this very reason to be considered inadmissible. It can be 
summed up in the following words of its author. 
“Each cell concerned in the ontogenesis in so far as it 
possesses a nucleus really carries within it the sum total 
of all anlagen; in so far however as it possesses a specific 
