MAMMALIA 459 



in higher forms much convoluted. Mammae chiefly thoracic 

 (abdominal in some lower forms). The group embraces the 

 lemurs, monkeys of various kinds, baboons with non-prehensile 

 tails, the tailless apes most like man, and man himself. While 

 the primates have produced some species with the highest in- 

 telligence to be found among mammals, and man places himself 

 at the head of the animal series, many of the bodily character- 

 istics of the primates are rather primitive. For example, the 

 habit of walking on the whole foot (plantigrade), the nails, the 

 teeth, and many other structures are regarded as more primitive 

 and less specialized than corresponding structures in such groups 

 as the carnivores or ungulates. We are more near the center 

 of the shaft of evolution. (See Fig. 251). 

 The chief divisions of the primates are: 



1. Lemuridae, or lemurs. 



2. New World monkeys, with broad and flat noses. 



3. Old World monkeys, having narrower nose with more 

 bridge. 



4. The man-like apes of the Old World. 



5. Some intermediate extinct types of man. (Found in 

 caves of Europe.) 



6. The Genus Homo, modern man. 



The primates below man are found chiefly in tropical regions 

 and more abundantly south of the equator. They feed largely 

 on fruit and insects, though some eat birds and other small 

 animals. Many of them are social, or at least gregarious, and 

 their habits of life are interesting and suggestive in a high degree, 

 when we consider their possible relation to the human species. 



464. Additional Notes on the Habits of Mammals. We 



have seen that mammals have succeeded in occupying in over- 

 whelming numbers the land, in much less degree the water, and 

 least of all the air. We have classified them as insectivorous 

 (moles, ant-eaters, and bats) ; carnivorous, as the beasts of prey; 

 herbivorous, as the hoofed animals, rodents, and kangaroo; or 

 omnivorous, as the pigs and man. They are very versatile 

 and have dominated the earth since the tertiary epoch when 

 they supplanted the immense reptiles of the earlier ages. 



