82 CREATIVE EVOLUTION [chap. 



quired peculiarity in the experiments of Brown-S6quard 

 can be explained by the effect of a toxin on the germ. The 

 lesion, however well localized it seems, is transmitted by 

 the same process as, for instance, the taint of alcoholism. 

 But may it not be the same in the case of every acquired 

 peculiarity that has become hereditary? 



There is, indeed, one point on which both those who 

 affirm and those who deny the transmissibility of acquired 

 characters are agreed, namely, that certain influences, 

 such as that of alcohol, can affect at the same time both 

 the living being and the germ-plasm it contains. In such 

 case, there is inheritance of a defect, and the result is 

 as if the soma of the parent had acted on the germ-plasm, 

 although in reality soma and plasma have simply both 

 suffered the action of the same cause. Now, suppose 

 that the soma can influence the germ-plasm, as those 

 believe who hold that acquired characters are trans- 

 missible. Is not the most natural hypothesis to suppose 

 that things happen in this second case as in the first, and 

 that the direct effect of the influence of the soma is a 

 general alteration of the germ-plasm? If this is the case, 

 it is by exception, and in some sort by accident, that the 

 modification of the descendant is the same as that of the 

 parent. It is like the hereditability of the alcoholic taint: 

 it passes from father to children, but it may take a different 

 form in each child, and in none of them be like what it 

 was in the father. Let the letter C represent the change 

 in the plasm, C being either positive or negative, that is to 

 say, showing either the gain or loss of certain substances. 

 The effect will not be an exact reproduction of the cause, 

 nor will the change in the germ-plasm, provoked by a cer- 

 tain modification of a certain part of the soma, determine 

 a similar modification of the corresponding part of the 

 new organism in process of formation, unless all the other 



