CHAPTER IX. 

 The Crossing and the Close-Interbreeding of Pigs. 



Of the smaller animals, the Pigeon, and the Fowl, 

 as we have seen, show adaptation to man's use or 

 fancy, at the greatest expense to their structural integ- 

 rity. The results are, great disproportionate develop- 

 ment and, as a necessary consequence of this, the 

 greatest degree of the evils which are occasioned by 

 close-interbreeding. In all of the larger animals, except 

 the Pig, adaptation to man's use, has harmonized, to a 

 greater or less degree, with the development, in each 

 individual, of all the characters of its species. 



With the Pig, as has just been remarked, it is other-, 

 wise. This species is the most disproportionately 

 developed, of all the larger animals, under domestica- 

 tion. The disproportionate development, however, i$ 

 due to a different occasion, from that which has entailed 

 the abnormal structures of varieties of the Fowl, and 

 of the Pigeon. In these species, under domestication, 

 the false ratio of the development of their characters, 

 is due, principally, to man's selecting, as the peculiarity 

 of each variety, one only of the characters which were 

 reduced or suppressed, under nature ; and to his push- 

 ing the development of that character, to an extreme 



point. Thus, while all of the characters of the species, 

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