THE ALLIES OF THE SQUIRREL: MAMMALIA 427 



had fallen overboard. That all monkeys are fond of play, 

 especially when young, is notorious ; they have a keen sense 

 of the ludicrous and enjoy exciting laughter, but they resent 

 being jeered at and may revenge themselves, as in the case 

 of a Cape baboon, who bespattered with mud an officer in 

 his dress uniform who had offended him." 



Professor Thorndike closes an article in the Popular Science 

 Monthly for July, 1901, in a way which serves to bring out 

 the intermediate position of the monkeys between man and 

 the lower mammals. He says : " In their method of learning, 

 although monkeys do not reach the human stage of a rich 

 life of ideas, yet they carry the animal method of learning, 

 by the selection of impulses and association of them with 

 different sense-impressions, to a point beyond that reached 

 by any other of the lower animals. In this, too, they resem- 

 ble man ; for he differs from the lower animals not only in 

 the possession of a new sort of intelligence but also in the 

 tremendous extension of that sort which he has in common 

 with them. A fish learns slowly a few simple habits. Man 

 learns quickly an infinitude of habits that may be highly 

 complex. Dogs and cats learn more than the fish, while 

 monkeys learn more than they. In the number of things he 

 learns, the complex habits he can form, the variety of lines 

 along which he can learn them, and in their permanence 

 when once formed, the monkey justifies his inclusion with 

 man in a separate mental genus." 



Economic Importance of Mammals. The mammals come 

 into more intimate relations with man than any other group 

 of animals. From them he gets materials for dress, wool, 

 leather, and furs ; food in the shape of butter, cheese, and 

 meat of different kinds. They are his beasts of burden the 

 world over, and they furnish a long line of miscellaneous 

 products such as horn, bone, ivory, perfumes, whalebone, 

 oils, fats, and material for fertilizers. 



