I VARIATION UNDER DOMESTICATION n^^, 39 " 



chances almost compels us to attribute its reappearance 

 to inheritance. Every one must have heard of cases of 

 albinism, prickly skin, hairy bodies, etc., 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. Pephaps__jthe_^orrecX_J£§!X^-ol--^^ /) 



whole^-sabjfigt^ would_JbeT-4o look -at_ the_ inheritance of | / 

 every character whatever as the rule, and non-inheritance ]3 

 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 commonly but not 

 exclusively to the like sex. It is a fact of some im- — 

 portance to us that peculiarities appearing in the males 

 of our domestic breeds are often transmitted, either exclu- 

 sively 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 reappear in the offspring at a 

 corresponding age, though sometimes earlier. In many 

 cases this could not be otherwise; thus the inherited 

 peculiarities in the horns of cattle could appear only 

 in the offspring when nearly mature; peculiarities in the 

 silkworm are known to appear at the corresponding cater- 

 pillar or cocoon stage. But hereditary diseases and some 

 other facts make me believe that the rule has a wider 



