SKELETAL SYSTEM 



373 



Kneecap patella 

 Ankle 7 tarsals 

 Foot 5 metatarsals 



each toe, except the big 



toe, which has two 



Scapula 



Pelvis 



Hum ems 



Peimu 



Fingers 14 phalanges, 3 



in each finger and 2 in 



the thumb 



Leg tibia and fibula 

 Thigh femur 



Composition 

 of bone. If we place 

 a rib in a bottle of 

 dilute hydrochloric 

 acid and let it stand 

 a few days, we shall 

 find that it has 

 changed. The shape 

 remains the same, but 

 the bone becomes soft 

 and elastic. It can 

 easily be cut with a 

 knife, and it will be 

 found to be so flexible 

 that it can be tied in 

 a knot. The sub- 

 stance of which it is 

 now composed is ani- 

 mal matter, or carti- 

 lage. 



By burning a bone 

 in a fire this animal matter can be removed. Again the 

 form of the bone does not change. After this process, 

 however, the bone is left white and brittle. The sub- 



Paiella ( 



adiirs 



ajpajs 



hafanges 



Fig. 171. 



-Tarsals 

 Metatarsais 

 Phalanges 



Bones of the leg and the 

 arm. 



