272 Theories Treating of Inheritance 
whatever; but natural selection (which acts in each cell 
of the organism among the different plastidular varia- 
tions) intervenes and fixes only those which are adapted 
to the new conditions of equilibrium.” ?°¢ 
We would just remark here, that the alteration 
undergone by the molar movements within each cell will 
be different in the different cells. For it would be incom- 
prehensible how in the very complex structure of the 
organism, a local change of form, imposed by external 
agents, could induce quite identical alterations in the 
molar movements of all the other cells of the body 
indiscriminately. Consequently the alterations of the liv- 
ing substance which internal natural selection preserves 
as fittest will likewise be different in different cells. How 
then can there be any question of the survival, in con- 
sequence of this internal natural selection, of one single 
plastidular variation identical at all points of the 
organism? 
LeDantec, like Hertwig, has recourse to the example 
of immunization. But as we have already seen, this 
case is quite different from the more or less local changes 
of form, which individuals experience in consequence of 
particular functional adaptations. In the case of immuni- 
zation the transforming cause, i. e. antibacterion, is the 
same for all cells. In the case of a morphological 
alteration on the contrary the transforming cause, that 
is, as we would concede it, the variation experienced by 
the molar movement concerned, is different in each cell. 
Even if one were willing to assume an identical 
variation of the living substance at all points of the 
organism indiscriminately, that would not explain the 
2°67 e Dantec: Ibid. P. 270, 208. 
