CHAPTER VIII 
MAMMALS 
102. The Mammals are the most highly developed of the 
vertebrates. They are warm blooded (the body tempera¬ 
ture remaining the same in winter and summer), breathe 
by means of lungs, and 
are provided with milk 
glands to nourish their 
young. Most mammals 
Figure 113. — Skeleton of 
* a Dog. 
Fi gure 114. — Coyote. 
These animals do many thousand dol¬ 
lars of damage annually to the breeders 
of cattle and sheep in the Western 
States. 
are covered with hair. A muscular wall (diaphragm) sub¬ 
divides the body cavity into two parts. The anterior part 
contains the heart and lungs, and the posterior part con¬ 
tains the stomach, intestines, liver, and other organs. At 
birth the young look like the parents. 
Most mammals have two pairs of limbs. The fore limbs 
may be variously modified for different uses, as for walk¬ 
ing in animals like the horse, for climbing and for food- 
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