NATURAL SELECTION 95 



lost character might, as was formerly remarked, for all 

 that we can see to the contrary, be transmitted for 

 almost any number of generations. (e) When a 

 character which has been lost in a breed reappears 

 after a great number of generations, the most probable 

 hypothesis is, not that one individual suddenly takes 

 after an ancestor removed by some hundred generations, 

 but that in each successive generation the character 

 in question has been lying latent, and at last, under 

 unknown favourable conditions, is developed. (/) 

 With the barb pigeon, for instance, which very rarely 

 produces a blue bird, it is probable that there is a 

 latent tendency in each generation to produce blue 

 plumage. The abstract improbability of such a 

 tendency being transmitted through a vast number of 

 generations is not greater than that of quite useless or 

 rudimentary organs being similarly transmitted. A 

 mere tendency to produce a rudiment is indeed some- 

 times thus inherited." 



In discussing the above paragraph, I shall not 

 hurry over the ground, as the whole question of the 

 inheritance of individual differences is involved. 



(a) It would not only be very surprising, it would 

 be absolutely miraculous, if characters, whether generic 

 or individual, should, as the effect of inheritance, 

 reappear " after having been lost for many, probably for 

 hundreds of generations." 



In the case of generic characters, the fact of their 

 having entirely disappeared for so long would signify 

 that their tendency to reappear had died out of the 



