310 



MAMMALIA. 



itself of deviating one iota from those peculiar instincts 

 which were given it by Grod. But Man at every effort rises 

 higher than he was before, till he arrives at such a knowledge 

 of the great works and designs of his Creator that he bows 

 his head in awe and admiration of the wonders permitted 

 to appear to his comprehension. "With respect to his bodily 

 structure, Man undoubtedly stands first in the race of 

 beings, although, in some particulars, such as the acuteness 

 of the senses, he may be inferior to some. 



The Human frame consists of a skeleton (fig. 73) formed of 

 hard and unyielding bone, having joints to admit of motion in 

 certain directions ; this skeleton performs certain great and 

 important offices, it forms strong boundaries or protecting 

 cases for most of the vital parts, so as to shield them from 

 external violence, such as the brain and spinal cord, the 

 lungs, heart, &c., it also furnishes a series of levers to be 

 acted on by the muscles, for the purposes of motion, and a 

 firm support for the soft parts of the system. The skeleton 

 is divided into the head, trunk, and extremities ; the head 

 is again divided into cranium and face ; the trunk is divided 

 into spine, thorax, and pelvis ; the 

 extremities intothe upper and lower, 

 the upper consisting of arm, fore- 

 arm, and hand ; the lower of thigh, 

 leg, and foot. The bones are divi- 

 ded into " flat bones " (fig. 74) and 

 "longbones" (fig. 75), the flat bones 

 (as a general rule) form the boun- 

 daries of the cavities, and the long 

 bones the levers. 



The bones consist of earthy mat- 

 ter, chiefly phosphate of lime, held 

 together by a sort of cartilage, and 

 arranged in fine scales or plates 

 forming interstices or cells (fig. 76), PIG. 74. FLAT BONE (Scapula), 

 these are large in the centre of the bone so as to make it nearly 

 (and in some instances quite) hollow, and very small at the 

 surface, so as to make it there nearly solid ; this arrangement 

 is found to be the very best to secure strength and lightness. 



