The Framework of the Body 



the joints and where it is protected 

 with cartilage. The periosteum is 

 richly supplied with blood vessels, and 

 plays an important part in the growth, 

 formation, and repair of the outside 

 of bone. If, therefore, the periosteum 

 be detached from the surface of the 

 bone by injury or disease, there is a 

 risk that a layer of the subjacent 

 bone will gradually lose its vitality 

 and soon die. 1 



35, Microscopic Structure of Bone. 

 If a very thin slice of bone be cut 

 from the compact tissue and examined 

 under a microscope, numerous minute 

 openings are seen. 2 Around these are 

 arranged rings of bone, with little 

 black bodies .in them, from which 

 radiate fine dark lines. These open- 

 ings are sections of canals called 

 Haversian canals, after Havers, an 

 English physician, who first discovered 



1 The periosteum is often of great practical 

 importance to the surgeon. Instances are on 

 record where bones have been removed, leaving 

 the periosteum, within which the entire bone 

 has grown again. Some years ago Dr. James 

 R. Wood, a famous surgeon in New York, 

 removed the whole lower jawbone from a young 

 woman, leaving the periosteum and even retain- 

 ing in position the teeth by a special apparatus. 

 The entire jawbone grew again, and the teeth 

 resumed their original places as it grew. 



2 Mounted sections of bone and slides for the 

 study of other elementary tissues may be readily 

 procured of dealers in microscopical supplies'. 



FIG. 14. Cross-Section 

 from Shaft of a Long 

 Bone. 



(Little openings (Haversian 

 canals) are seen, and 

 around them are arranged 

 rings of bone with little 

 dark spaces, lacuna, 

 from which branch out 

 fine dark lines, canali- 

 culi.) 



