682 . ZOOLOGY. 
It would appear, then, that animals have in some slight 
degree what we call mind, with its threefold divisions of the 
sensibilities, intellect, and will. When we study animals in 
a state of domestication, especially the dog or horse, we 
know that they are capable of some degree of education, 
and that they transmit the new traits or habits which they 
have been taught to their offspring; so that what in the 
parents were newly acquired: habits become in the descend- 
ants instinctive acts. We are thus led to suppose that the 
terse definition of instinct by Murphy, that.it is “‘ the sum 
of inherited habits,’’ is in accordance with observed facts. 
Indeed, if animals have sufficient intelligence to meet the 
extraordinary emergencies of their lives, their daily, so- 
called instinctive acts, requiring a minimum expenditure of 
mental energy, may have originated in previous genera- 
tions, and this suggests that the instincts of the present. 
generation may be the sum total of the inherited mental ex- 
periences of former generations. 
Descartes believed that animals are automata. Lamarck 
expressed the opinion that instincts were due to certain in- 
herent inclinations arising from habits impressed upon the 
organs of the animals concerned in producing them. 
Darwin does not attempt any definition of instinct ; but. 
he suggests that ‘‘ several distinct mental actions are com- 
monly embraced by this term,’’ and adds that ‘a little 
dose, as Pierre Huber expresses it, of judgment or reason 
often comes into play, even in animals low in the scale of 
nature.’’ He indicates the points of resemblance between 
instincts and habits, shows that habitual action may become 
inherited, especially in animals under domestication ; and 
since habitual action does sometimes become inherited, he 
thinks it follows that ‘‘ the resemblance between what origi- 
nally was a habit and an instinct becomes so close as not to 
be distinguished.’’ He concludes that, by natural selection, 
slight modifications of instinct which are in any way useful 
accumulate, and thus animals have slowly and gradu- 
ally, ‘‘ as small consequences of one general law,’’ acquired, 
through successive generations, their power of acting in- 
