CHAPTER X. 



The Crossing and Close-Jnterbreeding of Horses, 

 Sheep and Cattle. v 



It has been shown, that, with Fowls and Pigeons, the 

 multiplicity of divergent varieties, observable in either 

 of these species, involves great disproportionate de- 

 velopment of the individual ; and, comformably to the 

 theory adduced in this work, it has been found, by 

 reference to the phenomena recorded by Darwin, that 

 such individuals are peculiarly susceptible to the evils 

 occasioned by interbreeding. 



With the Pig, although there is no or very little di- 

 vergence of character, a failure in proportion of the 

 characters, has been caused, by a process of degenera- 

 tion, persisted in by Man, through a very mistaken 

 sense of policy. It has, likewise, been shown by Dar- 

 win's facts, that very great evil results from the reduc- 

 tion of the characters of the Pig. 



It is now designed to show, that with those species, 



under domestication, whose individuals approximate 



the true type of their respective species, there is an 



almost complete exemption from the evils of lessened 



fertility, and of lessened constitutional vigor, however 



long and closely, the individuals may be interbred. It 



must be remembered, that it is not necessary to show 

 (298) 



