NATURAL HISTORY. 
CHAPTER I. 
CLASSIFICATION OF ANIMALS. 
7 i. Tue Animal Kingdom has four grand divisions, or 
sub-kingdoms: the Vertebrates, the Articulates, the Mol- 
lusks, and the Radiates. @fi,se4Acv 
2. The animals of the vertebrate sub-kingdom have a 
frame-work, or skeleton of bones, inside, covered up by 
some of the soft parts of the body. In Fig. 1 (p. 14) 
you have the skeleton of man. You see that somewhat 
round box of bones which contains the brain; the col- 
umn of bones, 24 in number, extending from this through 
the trunk of the body; the pelvis, consisting of a wedge- 
shaped bone supporting this column and two broad, 
flaring bones, m and 7, on each side; the breast-bone, 
with the ribs extending from it to the column of bones 
in the rear, and the collar-bone, g, stretching from it as 
a prop to the top of the shoulder joint; the arm-bone, ¢, 
with the two bones of the forearm, 7 and 0, and the nu- 
merous small bones of the hand; the thigh-bones; the 
bones of the leg, » and w«, and those of the foot of about 
the same number with those of the hand. 
3. That part of the skeleton in which man is like a 
5 great variety of other animals is the central 
column of bones, and this is therefore taken as 
the characteristic of the division including man 
and these animals. In Fig. 2 you have one of 
the bones of this cclumn, @ being its front part, 
ree and 6 the sharp rear part, termed the spinous 
gle Vertebra. process. Itis the row of these rear sharp parts 
