GERMINAL SELECTION. 47 



tions, cannot be reduced to the processes of augmenta- 

 tion described, inasmuch as these, by their very na- 

 ture, can be effected only in living elements 

 capable of increase by propagation; but the interfer- 

 ence of selection does not begin originally with the 

 constitutional predisposition (Anlagen) of the germ, 

 i. e. with the determinants, but with the uhimate units 

 of life, the biophores. 



A determinant must be composed of heterogeneous 

 biophores, and on their numerical proportion reposes, 

 according to our hypothesis, their specific nature. If 

 that proportion is altered, so also is the character of 

 the determinant. But disturbances of this numerical 

 proportion must result at once on proof of their use- 

 fulness, or as soon as the modifications deter- 

 mined thereby in the inward character of the deter- 

 minant turn out to be of utility. For fluctuations of 

 nutriment and the struggle for nutriment, with its| 

 sequent preference of the strongest, must take place! 

 between the various species of the biophores as well as 

 between the species of the determinants. But changes 

 in the (quantitative ratios of the biophores appear to 

 us qualitative ^hanges^ ip_the corresponding deter- 

 mmants, somewhat as a simple augmentation of a 

 determinant, for example, that of a hair, may on its 

 development appear to us as a qualitative change, a 

 spot on the skin where previously only isolated hairs 

 stood being now densely crowded with them, and as- 

 suming thus the character of a downy piece of fur. 

 The single hair need not have changed in this process, 

 and yet the spot has virtually undergone a qualitative 

 modification.' The majority of the changes that appear f 

 to us qualitative rest on invisible quantitative changes, 

 and such can be produced at all times and at all stages I 



