1896.] A New Factor in Evolution. 545 
How do these movement variations come to be produced when 
and where they are needed?® And with it, the question: How 
does the organism keep those movements going which are thus 
selected, and suppress those which are not selected ? 
“ Now these two questions are the ones which the biologists 
fail to answer. But the force of the facts leads to the hypoth- 
eses of “conscious force,” “self-development” of Henslow 
and “ directive tendency ” of the American school—all aspects 
of the new Vitalism which just these questions and the 
facts which they rest upon are now forcing to the front. Have — 
we anything definite, drawn from the study of the individual 
on the psychological side, to substitute for these confessedly 
vague biological phrases? Spencer gave an answer in a 
general way long ago to the second of these questions, by say- 
ing that in consciousness the function of pleasure and pain is 
just to keep some actions or movements going and to suppress 
others. 
“ But as soon as we enquire more closely into the actual 
working of pleasure and pain reactions, we find an answer 
suggested to the first question also, i: e., the question as to how | 
the organism comes to make the kind and sort of movements 
which the environment calls for—the movement variations when 
and where they are required. The pleasure or pain produced by 
a stimulus—and by a movement also, for the utility of move- 
ment is always that it secures stimulation of this sort or that 
—does not lead to diffused, neutral, and characterless move- 
ments, as Spencer and Bain suppose; this is disputed no less 
by the infant’s movements than by the actions of unicellular 
creatures. There are characteristic differences in vital move- 
6 This is just the question that Weismann seeks to answer (in respect to the sup- 
ly of variations in forms which the paleontologists require), with his doctrine 
of ‘Germinal Selection ’ ( Monist, Jan., 1896). Why are not such applications of 
the principle of natural selection to variations in the parts and functions of the 
single organism just as reasonable and legitimate as it is to variations in separate 
organisms ? As against fs germin inal polartion,' hoeners, I may say, that in the 
rvival of ph logenetic 
Suraos a held in this paper) the hypothesis of germinal selection is in so far 
unnecessary. This view finds the operation of selection on functions in ontogeny 
the means of securing “ variations when and where they are wanted ;” while Weis- 
mann supposes competing germinal units. 
38 
