RICKETS. 477 



rounded on all sides by it and that cartilage is still 

 found at points where the bone ought long since to have 

 become transformed into medullary tissue. The farther 

 the process advances, the more, however, do we also meet 

 with isolated, scattered masses of lime in the cartilage, in 

 many instances to such a degree, that the whole of the 

 cartilage on section appears dotted with white points. The 

 irregularity of the process is further shown in this, that 

 whilst in the normal course of things the medullary spaces 

 should begin to form only at a short distance behind the 

 margin of calcifiation (Fig. 126), they here exceed these 

 limits, and in many cases a series of connective cavities 

 extends far beyond the border of calcification, which are 

 filled with a soft, slightly fibrous tissue, and besides have 

 vessels running up into them. Medullary spaces and 

 vessels are therefore met with, where normally and pro- 

 perly not a single medullary cell, and scarcely a single 

 vessel ought to be found. 



In this manner there may at all times be found side by 

 side in the parts, where the process has attained its height, 

 a whole series of different histological conditions. Whilst 

 in other cases we find at a certain definite point cartilage, 

 at another calcification, at a third, bone, or medullary 

 tissue, here everything lies in the greatest confusion ; in 

 one place, medullary tissue, above it osteoid tissue, or 

 bone, by its side calcified cartilage, and below it, perhaps, 

 cartilage still retaining its original condition. The whole 

 of the rhachitic portion of the diaphysal cartilage and it 

 may extend for a considerable distance of course acquires 

 no real firmness, and this is one of the chief causes of the 

 liability to distortion, which ricketty bones exhibit, not 

 in the continuity of the diaphyses, but at the articular 

 ends. This is in many cases extremely considerable and 

 is the sole cause of many a deformity, as, for example, 

 in the thorax. The curvatures in the continuity of the 



