oJi VERTEBRATA : MAMMALIA. 



We may now consider the motatory apparatus, or the 

 skeleton, the muscles, the ligaments, and the tendons. 

 The general structure of the skeleton of Mammals may be 

 seen in Figs. 2i and 60. This general structure is modi- 

 tied in eacli order, according to the functions which the 

 animals are to perform. 



In the adult mammals the skeleton is very hard and solid, 



FIG. 60. 



Skeleton ol the Lion (Felts leo). 



C, cervical vertebrae; D, dorsal vertebrae; L, lumbar vertebrae; 51, scapula; 53, 

 humerus; 54, ulna; 55, radius; 56, carpus; 58, position of the clavicles reduced to 

 clavicular bones suspended in the flesh; 62, 63, 64, pelvis; 65, femur; 06, tibia; 67, 

 fibula; 66', patella; 67', fabella ; i, ii, iii, etc., digits. 



but in the very young it is cartilaginous. The ossifica- 

 tion, or bone-making, begins, as already stated on page 32, 

 at various points in the cartilage, but these gradually co 

 alesce as the animal grows older. 



To prove that cartilage is the basis of all the bones which make up 

 the skeleton, it is only necessary to place any bone in weak muriatic 

 acid, which dissolves out the mineral substances and leaves the car- 

 tilage of the same form and size as the bone itself. 



