Chap. I.] VARIATION UNDER DOMESTICATION. 15 



and we see it in the father and child, we cannot tell 

 whether it may not be due to the same cause having 

 acted on both; but when amongst individuals, ap- 

 parently exposed to the same conditions, any very rare 

 deviation, due to some extraordinary combination of 

 circumstances, appears in the parent—say, once amongst 

 several million individuals — and it reappears in the 

 child, the mere doctrine of chances almost compels us 

 to attribute its reappearance to inheritance. Every 

 one must have heard of cases of albinism, prickly skin, 

 hairy bodies, &c., appearing in several members of the 

 same family. If strange and rare deviations of struc- 

 ture are really inherited, less strange and commoner 

 deviations may be freely admitted to be inheritable. 

 Perhaps the correct way of viewing the whole sub- 

 ject would be, to look at the inheritance of every 

 character whatever as the rule, and non-inheritance as 

 the anomaly. 



The laws governing inheritance are for the most part 

 unknown. No one can say why the same peculiarity 

 in different individuals of the same species, or in dif- 

 ferent species, is sometimes inherited and sometimes not 

 so; why the child often reverts in certain characters 

 to its grandfather or grandmother or more remote an- 

 cestor; why a peculiarity is often transmitted from 

 one sex to both sexes, or to one sex alone, more com- 

 monly but not exclusively to the like sex. It is a fact 

 of some importance to us, that peculiarities appearing 

 in the males of our domestic breeds are often trans- 

 mitted, either exclusively or in a much greater degree, 

 to the males alone. A much more important rule, 

 which I think may be trusted, is that, at whatever 

 period of life a peculiarity first appears, it tends to 



