64 An Examination of Weismannism. 



therefore necessary to quote some of these con- 

 cessions, if only to justify ourselves in subsequently 

 ignoring them. I will give one instance of each ; 

 but it is necessary to preface the illustrations with 

 a few words to mark emphatically three very 

 distinct cases of congenital variation — leaving aside 

 for the present the question whether or not they all 

 occur in fact, as they are held to do by one or other 

 of the theories of heredity. 



1. The case where impoverished nutrition of the 

 body has the effect of simply starving its germinal 

 material. This is not a case where either the continuity 

 or the stability of such material is affected. Its full 

 efficiency as " formative material " : may indeed be 

 thus deteriorated to any extent, so that the progeny 

 may be to any extent puny or malformed ; but this 

 will not necessarily cause any such re-shuffling of its 

 " molecules " as will thereafter result in a permanent 

 phylogenetic change. At most it will affect only the 

 immediate offspring of poorly nourished parents : and 

 natural selection will always be ready to eliminate 

 such inefficient individuals. This case I will always 

 hereafter call the case of nutritive congenital changes. 



2. The case where germinal material is influenced 

 by causes which do effect a re-shuffling of its '■ mole- 

 cules," so that a permanent phylogenetic change 

 does result. Observe, in this case, it does not signify 

 whether the causes arise from external conditions of 

 life, from any action of the soma on its own germinal 

 material, or from so-called ^spontaneous" changes 

 on the part of such material itself. But the one 

 cause which has not been concerned in producing an 

 hereditary modification of this class is the mixture 



