THE SKELETON 261 



Any kind of dress which presses upon the bones is sure to 

 result in deformity. If one wishes health, he should let his 

 body grow as nature intended and not curb it by confining 

 it in tight garments. If the boy or girl stands erect and is 

 not hampered by constricting clothing, the bones will develop 

 properly. The deformity of bowed legs, however, is not due, 

 as frequently supposed, to the fact that a child has been 

 allowed to walk too early. "Bow legs" are found chiefly among 

 poor children, and are caused by a disease called rickets, 

 brought on by improper food and lack of air and sunlight. 



Since so much in the way of body strength and usefulness 

 depends on the perfect condition of the skeleton, it is simply 

 a matter of common sense that care should be taken, espe- 

 cially with growing children, that the diet contain all mater- 

 ials necessary for bone making. Milk and its products, with 

 wheat and oat cereals, are valuable in this connection. 



Repaii of Broken Bones. The animal matter in a bone is 

 the only part of it which is alive, and it is this, therefore, 

 which effects its growth and repair. Each bone is provided 

 with tiny blood vessels which enter through small openings 

 and then branch into numerous vessels, running in every 

 direction inside the bone and furnishing the living parts with 

 materials for all necessary repairs. The bone is filled with 

 myriads of minute living cell bodies, called bone cells, which 

 have the power of making new bone material when necessary, 

 and thus of repairing broken bones. If a bone in the body is 

 broken and the ends are brought together, these living cells 

 begin at once to unite the two ends, and if allowed to continue 

 this work undisturbed for a few weeks, will completely join 

 them, making the bone as strong as ever. 



The value of the periosteum, too, in this matter of bone 

 repair is very great, for, being filled with blood capillaries it 

 can furnish new material. It has even been shown that the 

 periosteum, if not disturbed when a bone is taken out of the 

 body, can replace all the hard parts of the bone. 



