no COMMON MODES OF INHERITANCE 



for their expression in development. We can imagine the son 

 of a lavish millionaire reacting to plain living, the superficial 

 inference that the money had been lost, and the contradiction 

 of this in the third generation. 



Similarly, when a male offspring is compared with the mother, 

 a female offspring with the father, it is important to bear in mind 

 that the difference in sex may account for some of the apparent 

 differences in detailed characters. Through functional cor- 

 relation, the differentiation of sex may bring about the non- 

 expression or the modified expression of a peculiarity which was 

 none the less transmitted in its entirety as the third generation 

 may demonstrate. 



Another fact that must be borne in mind is the difficulty of 

 distinguishing even with probability between hereditary and 

 acquired resemblances. The Alpine plants which Nageli trans- 

 planted to a southern garden were changed by their new sur- 

 roundings ; their descendants were likewise changed, and the 

 new characters reappeared with constancy generation after 

 generation. But this was acquired or modificational, not 

 hereditary or innate resemblance, as was shown by the fact that 

 removal from the garden to poor gravelly soil was followed by 

 a reappearance of the original Alpine characteristics. Some 

 interesting cases have been alleged where the reappearance of 

 the Alpine characters was not immediate, but gradual. We 

 require, however, more circumstantial details in regard to these 

 cases. 



§ 3. Blended Inheritance 



In this mode the special characters of the two parents are 

 intimately mingled in the offspring. The colour of the hair 

 may be an almost precise average between that of the blonde 

 mother and that of the black-haired father. In repose the boy's 

 face may seem markedly paternal ; it is moved with emotion, 

 and he is his mother's image. This blending is particularly well 



