158 Instinct, 



vidual. In the case of some of the lower animals, 

 as insects, this effect is so marked that death almost 

 immediately follows, after provision has been made 

 for the continuance of the species. And among 

 mammals of every grade, not only is the production 

 of young a draft upon the animal pOAvers, but the 

 maintenance and defence ofthe young, lead animals 

 to encounter many dangers, to which they would 

 not otherwise be exposed. The instinctive love of 

 life, even, is often held in abeyance, by the instinct- 

 ive love of offspring ; so that animals expose them- 

 selves to death, in defence of their young. 



This instinct, that leads to the care ofthe young, 

 continues in full force while they need the care. 

 But in the case of some animals, that have been 

 carefully observed, it has been found that there 

 comes a time, when this instinct is reversed, so to 

 speak, — when the mother will drive from her the 

 young, which, a few days before, she would have 

 risked her life in defence of. It is interesting to 

 see the entire change that takes place, sometimes, 

 in a single day. As long as the hen appears with 

 ruffled feathers and an angry sounding cluck, she 

 is ready to fight for her chickens ; but all of a sud- 

 den, her feathers are smooth, her voice changes 

 from the cluck to a musical note ; and then she 

 fiercely drives her young from her. Her Instinct 

 has now completed its round. Every peculiar in- 

 stinct of motherhood appeared, as the production 

 of young and their protection required it. Each 

 one appeared in connection with certain bodily 

 functions, over which she had no control. When 



