'PRINCIPLES OF HEREDITY 



characters are due to these causes, and reappear generation 

 after generation, and may even to a certain extent be 

 intensified with time, that by no means proves that 

 these characters are inherited. On the contrary, there is 

 evidence to show that the same character is merely re- 

 imposed on each successive generation, as it is exposed to 

 the same environmental conditions. It is, in other words, 

 an individual acquirement, re- acquired by each following 

 generation. This follows clearly from the fact that when 

 the plants mentioned were taken back into poor gravelly 

 soil they at once lost their assumed character, and 

 once more presented the appearance of the original 

 Alpine plants. If the acquired character had actually 

 become part and parcel of the individual inheritance, 

 it should have persisted for at least some generations 

 after retransplantation of the plants into their normal 

 habitat. 



There has been a good deal of discussion about the 

 physical degeneration of the people. It has been said that, 

 on account of the unhealthy and wretched conditions the 

 poor have to live in and to work under, the physique of the 

 modern worker has deteriorated to an alarming extent. 

 There is no doubt, the present-day slum and factory life 

 has a most deleterious effect on the individual, but 

 whether such bad result is in itself transmitted to the 

 children is by no means decided. There is nothing to 

 show that the progeny of such individual, if removed early 

 enough into healthy surroundings, would not grow up 

 perfectly sound and normal. The stunted and weakly 

 appearance of such children can easily be accounted for in 

 another way. Firstly, the children of the poor are sub- 

 jected from the very first days of their lives to the same 

 unwholesome and grinding conditions of existence as their 

 parents ; and, secondly, the state of the mother, who is 

 generally underfed and overworked, is bound to have a 

 harmful influence on the child even before birth. Con- 

 genital weakness is in most of these cases nothing but the 



