Chap. I.] VAEIATION TJNDEK DOMESTICATION. 15 



pears, 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, 

 apparently 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 com- 

 pels 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 structure are really inherited, less strange 

 and commoner deviations may be freely admitted to be 

 inheritable. Perhaps the correct way of viewing the 

 whole subject would be, to look at the inheritance of 

 every character whatever as the rule, and non-in- 

 heritance 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 

 different species, is sometimes inherited and sometimes 

 not so ; why the child often reverts in certain characters 

 to its grandfather or grandmother or more remote 

 ancestor ; 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 



