16 THE MENDEL JOURNAL 



but rather would tend to obliterate had environment 

 a power to do so. The fact that these differences are 

 not obliterated, even among those living in the same 

 social atmosphere, is a strong argument in favour of 

 germ-plasm causation. The more minutely one 

 studies separate families and traces them through 

 succeeding generations the more one is convinced 

 that the welfare of the family and consequently the 

 nation depends on stock. At the same time, the more 

 one seeks an explanation for the facts of family 

 variation in any humanly imposed or artificially 

 created atmosphere of surroundings the more one 

 finds his expectations fail. 



