THE SKELETON. 101 



the scapula somewhat, and is called the ilium ; the second, placed 

 in front, called the pubis, may, perhaps compare with the clavi- 

 cle, and the third, situated below and behind, has received the 

 name of isc/tiunt, and which supports the whole weight of the 

 body when seated ; with age these three bones become solidified 

 into one. At the point where they unite, we find a very deep, 

 circular cavity called the coiyloid or more commonly the accta 

 bttlum, in which is articulated the thigh bone. 



51. The pelvis serves not only to support the lower extremi- 

 ties, but also assists in sustaining the weight of the viscera con- 

 tained in the abdomen, and in forming the parietes of this cavity. 



52. The thiy/t is formed of a single bone called the femur, 

 This bone is articulated by its superior extremity with the hip 

 bone, and by its inferior extremity with the leg. 



53. The teg is formed of two bones very solidly united to each 

 other. The bone placed internally, very much larger than the 

 other and called tibia articulates with the femur by its superior 

 extremity. The bone which is placed externally does not quite 

 reach to the femur, and is only united to the tibia ; it is named 

 fibula. In front of the articulation of the leg with the thigh is 

 placed a small bone named rotula or patella, which is designed 

 to strengthen the knee joint. 



54. The font is divided into three regions; the tarsus, the- 

 metatarsus and tors. It differs from the hand chiefly in tne 

 shortness of the fingers, that is, toes, their limited mobility and 

 by the disposition of the tarsus. 



55. The tarsus is constituted of the union of seven bones, one 

 of which alone, called the astragalus, articulates with the two 

 bones of the leg ; another one of these bones, called the c/ci.v, 

 forms a considerable projection behind which constitutes the 

 heel. 



56. The metatarsus is composed of five bones which are united 

 to the tarsus and to the bones of the toes, and which are ar- 

 ranged like the bones of the metacarpus. 



57. Like the fingers, the toes are composed of p' alnnges. 

 called first, second, and third phalanges. The great toe ha-t but 



wo phalanges, each of the others has three. All th*H little 



51. What are th- uses of the pelvis '! 



5'2. What number of bones is in the thigh ? 



53. How many bones constitute the leg ? What are they callet 'Vhat i 

 he patella? 



54. How do-s the foot differ from the hand ? 



55. What constitutes the tarsus ? 



56 Of what bones is the metatarsus composed ? 

 5V Of why* hoaes arc the toes composed 1 

 9 



