18 
INTRODUCTORY. 
generally only fitted for progressive motion on the earth; which 
they can sustain with long endurance. A few species can, how¬ 
ever, mount into the air, by means of extensible membranes, 
attached to their limbs, which are usually much elongated; as 
in the bat tribe, &c.: while the cetaceous animals, and some 
others, are formed to move in the water only, from the short¬ 
ness of their limbs. 
Most of the generic and specific distinctions in the mam¬ 
malia are founded on the teeth, together with the size and 
shape, &c. of the bones of the animal skeleton. It must, there¬ 
fore, be apparent, that to understand these, a knowledge of the 
various principal bones of which the skeleton is composed be¬ 
comes absolutely necessary. Man being the most perfect of 
vertebrate animals, his skeleton contains all the parts which 
exist in other animals, which have vertebrae. It is the province 
of the comparative anatomist and zoologist to examine and com. 
pare these, as they exist in the various species, and upon his 
anatomical skill will depend the success of his investigations. 
We, therefore, give a view of the 
HUMAN SKELETON— Plate I. 
BONES OF THE TRUNK. 
A. The sternum. 
B. The seventh, or last true rib. 
C. The cartilage of the ribs. 
D. The twelfth, or false rib. 
E. The lumber vertebrae, with their intervertebral cartilages, 
and transverse processes. 
F. The os sacrum. 
G. The os innominatum, composed of 
The os ilium, a. 
The os pubis, b. 
The os ischium, c. 
BONES OF THE SUPERIOR EXTREMITY. 
H. The clavicle. 
I. Inner surface of the scapula. 
