Booh Notices. 495 



were hedged about by their " life in sensuism," to use his own 

 phrase ; he claimed for many of them high degrees of intel- 

 ligence, and used to entertain his students by relating to them 

 the results of his own observations and experiments with 

 bees, ants and other creatures, carried on much in the same 

 way as those of Dr. Wesley Mills. He especially maintained 

 that all creatures have a language of their own. And who 

 that has heard a squirrel or catbird scold, or a sentinel crow 

 give warning to the flock he belongs to of the approach of a 

 gunner, can doubt that they have a most effective capacity 

 of utterance ? 



Prof. Mills' second thesis is that the hereditary mental 

 capacity of the lower animals, which usually goes by the name 

 of instinct, is capable of great expansion, fro^m the moment of 

 the creature's birth until the time it has reached its full 

 growth and maturity. The series of observations he has 

 recorded go to show that while certain tokens of the possession 

 of power for gaining sustenance are exhibited from the first, 

 there is a rapid development of intelligence in the way of 

 experimental knowledge, on the part of each individual. Of 

 course, such acquirements as any animal makes by experi- 

 ence, have relation to the sphere it fills in the total sum of 

 being. Each species has its own functions and displays its 

 characteristic capacity and applies its intelligence in attaining 

 those functions, and whilst the individual species learn from 

 each other, by imitation and otherwise, they do not seem to 

 take lessons from beyond the limits of their own kind, unless, 

 indeed, domestic animals generally are helped upward in the 

 scale of being, as our author hints at, by their contact with 

 man. 



At the same time. Dr. Mills has given instances in which 

 Individuals have risen higher in intelligence than the ordinary 

 level of their species. Any one who has taken note of the 

 cats and dogs with which he has been acquainted, to go no 

 further, must have marked great differences in their capacity, 

 and in the degree of intelligence which they reached. In 

 herds of cattle, too, there is often one cow that has a power 

 of initiative that gives her pre-eminence, and often makes 

 her exceedingly troublesome. It may be that it was by 

 accident that she first learned to open the gate leading to 

 the cabbage garden ; but once having acquired such know- 

 ledge, it becomes hard to keep the " breachy " animal out 

 of mischief. The same is true of horses in breaking down 

 fences with their bodies, or in learning to jump the fences 



