Influence of Domestication. 159 



the functions ceased, the special Instincts ceased 

 with them. Her Instinct Is, henceforth, exercised 

 in the constant labor of self-protection and self-sup- 

 port, till a new round of duties begin, with the mak- 

 ing of a new nest. 



In the unnatural conditions under which many 

 of our domestic animals are kept, this Instinct, that 

 leads to the production and care of young, is appar- 

 ently modified, or kept in abeyance, by some 

 stronger instinct or change of function, that we do 

 not understand. Certain animals, as Elephants and 

 Eagles, never produce young while under the con- 

 trol of man ; and in other cases, certain instincts, 

 that continue to act to some extent, are weakened 

 and rendered Irregular In their action ; as in the 

 case of fowls, which produce eggs, but never brood ; 

 and sheep that will not own their young. 



When we consider how dependent Instinct is 

 upon function, and know how domestication inter- 

 feres with the natural habits of animals, and also 

 that the selection exercised by man, often comes 

 in to secure conditions of life that never would oc- 

 cur under the Influence of Natural Selection, we 

 shall be prepared to find many seeming anomalies 

 of Instinct among our domestic animals. These 

 anomalies may give us important information, as 

 to the original habits of these animals, or as to the 

 plasticity of their natures in the hand of man. 

 There is now, in Natural History, no more Inter- 

 esting field of observation than that offered by our 

 domestic animals, — no one, that promises more ad- 

 vantage to science, or to the money interests of the 



