452 



THE MAMMALS 



many of us become very fastidious about the odors around us and 

 complain about bad odors, such as the rotten egg odor of hydrogen 

 sulfide permeating the atmosphere of a school from the chemistry lab- 

 oratory. 



The primates have a single pair of mammary glands located in the 

 pectoral region of the body. This is correlated with their upright sitting 



Courtesy Chicago Natural History Museum 



Fig. 28.28. A woolly monkey from Ecuador. This typical new world monkey is 

 shown using its tail as a fifth prehensile limb. 



position, so the young can nurse without standing on their heads. The 

 young are born with a strong grasping instinct and, in most primates, 

 cling to the mother's body while she leaps around in the trees. Even the 

 human baby is born with this instinct and can grasp a limb strongly 

 enough to support its own weight a week or two after birth, but after this 

 the strength is lost and an older baby cannot thus support its body 

 weight. 



