40 ARE THE EFFECTS OF USE INHERITED ? 



that in his own structural cells, which have led 

 to an alteration in the quality of his own nerves. 

 Exactly the same must occur in the case of 

 many constitutional diseases that have been 

 acquired by long-continued irregular habits." l 



INDIVIDUAL AND TRANSMISSIBLE TYPE NOT 



MODIFIED ALIKE BY THE DIRECT EFFECT OF 



CHANGED HABITS OR CONDITIONS. 



Mr. Spencer finds it hard to believe that the 

 modifications conveyed to offspring are not iden- 

 tical in tendency with the changes effected in the 

 parent by altered use or habit (pp. 23-25, 34). 

 But it is perfectly certain that the two sets of 

 effects do not necessarily correspond. The 

 effect of changed habits or conditions on the 

 individual is often very far from coinciding with 

 the effects on the reproductive elements or the 



1 Contemporary Review, December, 1875, p. 92. 



