52 AGRICULTURE. 



By atavism is meant that innate tendency in animals to 

 revert to the original type. It differs from the principle 

 that like produces like in the reproduction of resemblances 

 to an ancestry more or less remote rather than to the par- 

 ents, and differs from spontaneous variation in produc- 

 ing resemblances to an ancestry more remote than the im- 

 mediate parents, whereas the latter produces characters 

 unlike those of the ancestry, whether near or remote. Il- 

 lustrations of atavic transmission are found in the occa- 

 sional apearance of scars or horns in the polled breeds of 

 cattle bred pure for many successive generations, and in 

 the occasional appearance of tan-colored spots on the ears 

 and face of the American merino. 



It is evident, therefore, that an intimate knowledge of 

 the principles which govern breeding is highly important 

 to those engaged in the production of live-stock. Hence 

 they should study these with the utmost care and should em- 

 body them in their practice to the greatest possible extent. 



