Chap. XIII. 



REVERSION. 



55 



already seen that the transmission of a character from the 

 grandparent to the grandchild, with its apparent omission in 

 the intermediate parent of the opposite sex, becomes simple on 

 this view. When fowls, pigeons, or cattle of different colours 

 are crossed, and their offspring change colour as they grow 

 old, or when the crossed turbit acquired the characteristic frill 

 after its third moult, or when purely-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 transmitted 

 them to some of their offspring, which in this case would in 

 appearance have received such characters from their grand- 

 parents or more distant progenitors. We 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 con- 

 clude is what occurs with reversions of all kinds to progenitors, 

 however remote. 



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

 racters which appear through reversion, is also supported 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 early youth. Black 

 cats, we may feel assured, would occasionally produce by 

 reversion tabbies; and on young black kittens, with a pedi- 

 gree 63 known to have been long pure, faint traces of stripes 

 may almost always be seen which afterwards disappear. Horn- 

 less Suffolk cattle occasionally produce by reversion horned 

 animals; and Youatt 64 asserts that even in hornless individuals 



63 Carl Vogt, < Lectures on Man,' Eng. translat., 1864, p. 411 



64 On Cattle, p. 174. 



