30 INHERITANCE. Chap. XIII, 



their offspring change colour as they grow okl, or when the 

 crossed turbit acquired the characteristic frill after its third 

 moult, or when p arely-bred bantams partially assume the red 

 plumage of their prototype, we cannot doubt that these 

 qualities were from the first present, though latent, in the 

 individual animal, like the characters of a moth in the cater- 

 pillar. Now, if these animals had produced offspring before 

 they had acquired with advancing age their new characters, 

 nothing is more probable than that they would have trans- 

 mitted them to some of their offspring, who in this case would 

 in appearance have received such characters from their grand- 

 parents or more distant progenitors. AVe should then have 

 had a case of reversion, that is, of the reappearance in the 

 child of an ancestral character, actually present, though 

 during youth completely latent, in the parent ; and this we 

 may safely conclude is what occurs in all reversions to pro- 

 genitors, however remote. 



This view of the latency in each generation of all the cha- 

 racters which appear through reversion, is also sujDported by 

 their actual presence in some cases during early youth alone, 

 or by their more frequent appearance and greater distinctness 

 at this age than during maturity. We have seen that this is 

 often the case with the stripes on the legs and faces of the 

 several species of the horse-genus. The Himalayan rabbit, 

 when crossed, sometimes produces offspring which revert to 

 the parent silver-grey breed, and we have seen that in purely 

 bred animals pale-grey fur occasionally reappears during earl}^ 

 youth. Black cats, we may feel assured, would occasionally 

 produce by reversion tabbies ; and on young black kittens, 

 with a pedigree '^^ known to have been long pure, faint traces 

 of stripes may almost always be seen which afterwards dis- 

 appear. Hornless Suffolk cattle occasionally produce by 

 reversion horned animals ; and Youatt ''^ asserts that even in 

 hornless individuals " the rudiment of a horn may be often 

 felt at an early age." 



No doubt it appears at first sight in the highest degree im- 

 probable that in every horse of every generation there should 



«« Carl Vogt, ' Lectures on Man,' ^7 ; Qn Cattle,' p. 174. 



Eng. translat., 186-1, p. 411. 



