328 THE CROSSING, 4C, OF CATTLE, ET AL. 



larger than the female, is, as we shall see, when treat- 

 ing of generation, because the formative capacity of the 

 male element is of an exogenetic character, and has a 

 peculiar, but not an exclusive influence, over the de- 

 velopment of the periphery of the organism. 



With respect to the Crossing of Cattle, Darwin says 

 (p. 147, Vol. ii, Animals and Plants &c.) : 



" Although, by carefully selecting the best animals, 

 close-interbreeding may be long carried on with Cattle, 

 yet the good effects of a cross between almost any two 

 breeds, is at once shown by the greater size and vigor 

 of the offspring ; as Mr. Spooner writes to me, ' cross- 

 ing distinct breeds certainly improves Cattle, for the 

 butcher.' Such crossed animals are, of course, of no 

 value to the breeder, but they have been raised 

 during many years, in several parts of England, to be 

 slaughtered; and their merit is now so fully recognized, 

 that at fat-cattle shows, a separate class has been formed 

 for their reception. The best fat ox, at the great show 

 at Islington, in 1862, was a crossed animal." 



The reason why, as Darwin asserts, such crossed 

 animals, though " their merit is now so fully recog- 

 nized," " are of course of no value to the breeder," is, 

 because they will not persist in one type, but drop off- 

 spring, of every variety of improved types, though with 

 no one excellence predominant. They have, united, in 

 them, the peculiarities of two varieties, and this com- 

 bination stimulates all the other centres of growth. 

 The breeder desires to develop each excellence, in a 

 different variety. In one, he wishes to have fine meat- 

 producing qualities ; in another, quantity of milk ; in 

 another, good butter-making capacity, &c. On the 



