208 The American Naturalist. [March, 
directly to new environment by general variability, and even by + 
such special variations as above cited by Weismann ; but, keeping 
in mind the fortuitous principle, why do we also discover varia- 
tions, not merely in size and efflorescence,” but in the nature of 
direct adaptations? This point has recently been raised by 
Mivart, with his usual acuteness in destructive criticism. 
I do not consider that it has been demonstrated that Environ- 
ment does act directly upon the germ-cells. In the case of 
animals we certainly cannot determine how far the nervous and 
other somatic cells are mediate, besides the somatic cells of the. 
nutritive system. Yet in the acceleration of variability, and in the 
direct production of variations of Class II., we have examples of 
such rapid response to changed environment that the presumption 
is somewhat in favor of Weismann’s view. . In either case, such 
mediate action of certain somatic cells angat be advanced in 
support of Lamarck’s principle that the effects of environment on 
special groups of somatic cells make themselves felt in, or trans- 
mitted to the germ-cells in such a manner as to reappear in some 
degree in the same special groups of somatic cells in the new 
individual. Let us therefore concentrate our attention upon the 
evidence as to the possible modes of origin and transmission of 
variations in definite adaptive lines (Class III.). Three explana- 
tions are open to us: 1. That these adaptations have been 
selected from a number of variations of the fortuitous class; 2- 
That the germ-cells respond to environment by adaptive varia- 
tions ; 3. That the variations originate in adaptive reactions of the 
sini cells, under environment, which have been transmitted to 
the te -cells. Let us first consider the question of individual 
4: ia Jaod Variations adaption ?—I should hardly have 
thought it necessary to consider this question but for the fact that 
a recent writer, who claims the sanction of Mr. Romanes and Mr. 
Poulton, has advanced the proposition that the inheritance of 
‘Huxley has as analyzed — on the pure Selection hypothesis 1E 
direction, but favors and pinsi = 
tendency in that direction which already exists. . Conditions are not actively pro- 
ductive, but passively permissive.” ‘‘ Critiques aint Addresses,” p. 309- 
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