xvi] 



THE STRUCTURE OF BONE 



681 



In the case of the bird's wing-bone, the hollow of the bone is 

 practically empty, as we have already said, being filled only with 

 air save for a thin layer of living tissue immediately within the 

 cylinder of bone; but in our own bones, and all weight-carrying 

 bones in general, the hollow space is filled with marrow, blood- 

 vessels and other tissues ; and among these living tissues hes a 

 fine lattice- work of httle interlaced "trabeculae" of bone, forming 



Fig. 334. Head of the human femur in section. (After .Schiifer, from 

 a photo by Prof. A. Robinson.) 



the so-called "cancellous tissue." The older anatomists were 

 content to describe this cancellous tissue as a sort of "spongy 

 network," or irregular honeycomb, until, some fifty years ago, a 

 remarkable discovery was made regarding it. It was found by 

 Hermann Meyer (and afterwards shewn in greater detail by 

 Juhus WolfE and others) that the trabeculae, as seen in a longi- 

 tudinal section of a long bone, were arranged in a very definite 

 and orderly way ; in the femur, they spread in beautiful curving 



