MAMMALIA. 449 



of these higher instincts, thus making a new demand on the 

 parent for care and training. 



The social instinct is well represented among mammals. 

 This may vary from collection in mere shoals or herds where 

 food is abundant, to groups organized for offense and defense 

 and for work, as wolves, deer, beavers. Indiscriminate 

 mating is the rule, yet in some instances strict monogamy is 

 found. In many cases mates are won by force, and this tends 

 to result in the selection and propagation of the strong. The 

 struggle among the males is accompanied by the development 

 in them of numerous structures which the females do not pos- 

 sess at all or at least in such degree : as antlers, horns, tusks, 

 manes, and greater size. 



It is in the higher mammals that one finds the greatest dis- 

 play of intelligence to be seen in the animal kingdom, and it 

 is in man that intelligence and reason L whose beginnings in 

 animals no one can mark find their culmination. That these 

 high qualities are closely correlated with the great development 

 of the brain there can be no doubt. The great progress of man 

 in getting mastery of the earth is one of the most interesting 

 aspects of the same general problem of evolution and adapta- 

 tion which gives unity to the subject matter of zoology. 

 Thus the sciences which pertain to man in all his various in- 

 terests have in some measure their foundation in the science 

 of zoology. 



454. Supplementary Topics for Field and Library. 



1. Enumerate the native species of mammals known by you 

 to be found in your locality, and determine to which of the 

 orders of mammals they belong. Are you impressed that the 

 number of native species of mammals is large or small as com- 

 pared with other animals ? Are the individuals of these species 

 numerous or not ? How do you account for the facts you have 

 discovered ? 



2. Enumerate the species of domestic mammals in your lo- 

 cality. Are they related to any of the native species? Trace 



