430 



GENERAL ZOOLOGY 



mechanical manner to outside forces. Finally, after many 

 hundreds of experiments and many conflicts in definition of 

 terms, the students in animal behavior have come to the 

 conclusion that man is not the only animal possessing an 

 intellect. In the animals below man we find the beginnings 

 of reason and the various emotions. Very recently much 

 attention has been directed to the study of the intelligence 



of some of the higher 

 apes, especially the 

 chimpanzee and the 

 orang-utan. In a book 

 entitled Almost Hu- 

 man, Professor R. M. 

 Yerkes of Yale Uni- 

 versity has reviewed 

 a good many observa- 

 tions and interesting 

 experiments on the 

 higher apes. In one 

 experiment a banana 

 is placed above the 

 reach of a chimpan- 

 zee. He piles boxes one on top of another until he can 

 climb high enough to grasp it. Is it possible to explain 

 such behavior as accidental, requiring no mental activity? 

 Economic Importance of Mammals. The mammals come 

 into more intimate relations with man than any other group 

 of animals except the insects. 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. 

 The following paragraphs tell of other relations. 



Fig. 226. Portrait of a young chimpanzee 



Photograph by Elwin R. Sanborn, courtesy of 

 the New York Zoological Society 



