94 



or other colored pigeon, which may have transmitted 

 its proper color, during centuries, there should be a 

 latent capacity, in the plumage, to become, and to be 

 marked, with certain characteristic bars ; that, in every 

 child, in a six-fingered family, there should be the 

 capacity for the production of an additional digit; 

 and so in other cases. Nevertheless, there is no 

 more inherent improbability in this being the case, 

 than in a useless and rudimentary organ, or even in 

 only a tendency to the production of a rudimentary 

 organ, being inherited during millions of generations (!), 

 as is well known to occur with a multitude of organic 

 beings. There is no more inherent improbability, in 

 each domestic pig, during a thousand generations, re- 

 taining the capacity and tendency to develop great 

 tusks, under fitting conditions, than in the young calf 

 having retained, for an indefinite number of genera- 

 tions, rudimentary incisor teeth, which never protrude 

 through the gums." 



Again he says, on page 70, Vol. ii : 



"The subject of latent characters is so important, 

 as we shall see in a future chapter, that I will give 

 another illustration. Many animals have the right 

 and left sides of their body unequally developed: 

 this is well known to be the case with flat fish, in 

 which the one side differs, in thickness and colorf 

 and in the shape of the fins, from the other; and 

 during the growth of the young fish, one eye ac- 

 tually travels, as shown by Steenstrup, from the 

 lower to the upper surface. In most flat fishes, the 

 left is the blind side, but, in some, it is the right; 

 though, in both cases, 'wrong fishes,' which are 

 developed in a reversed manner to what is usual, 

 occasionally occur, and in Platessa flesus, the right 

 or left side is indifferently developed, the one as 

 often as the other. With gasteropods, or shell-fish, 



