SCOPE OF GENETICS 



We all know that a man may have his father's 

 hair, his mother's colour, his father's voice, 

 his mother's insensibility to music, and so on, 

 but that is not enough. 



Such an analysis is true, inasmuch as the 

 various characters are transmitted independ- 

 ently, but it misses the essential point. For in 

 each of these respects the individual is double; 

 and so to get a true picture of the composition 

 of the individual we have to think how each 

 of the two original gametes was provided in 

 the matter of height, hair, colour, mathe- 

 matical ability, nail-shape, and the other 

 features that go to make the man we know. 

 The contribution of each gamete in each 

 respect has thus to be separately brought to 

 account. If we could make a list of all the 

 ingredients that go to form a man and could 

 set out how he is constituted in respect of 

 each of them, it would not suffice to give one 



