THE FRAMEWORK OF THE BODY 



51 



On examination, one of the long bones in a fresh condi- 

 tion is seen to be covered at the two ends with smooth 

 white articular cartilage, while the shaft is inclosed in a 

 sheath of dense white fibrous membrane, called the peri- 

 osteum, closely adhering to it. It is on the inner side of 

 this membrane that the bone grows, and by it the nutri- 



Pelvic Bone 



Synovial Membrane 



Head of Femur 



-Round Ligament 



- Capsular Ligament 



Fig. 36. Section of hip joint. 



tion of the bone throughout life is assisted. If the peri- 

 osteum is torn away, the bone dies. It covers every part 

 of the surface of a bone not covered by the articular car- 

 tilage, and into it the fibers of the ligaments extend, being 

 so interwoven as to make an indistinguishable and insep- 

 arable junction. 



59. Inner Composition of Bone. If the bone is sawn 

 through from end to end, the shaft is found to be hollow, 

 with the medullary cavity, as it is called, in the center, 

 filled with yellow marrow. The walls of the shaft are 

 of a dense, solid structure, except for a thin stratum of 



