742 THE BONES AND JOINTS. 



and canuot resist the traction of the muscles or outside pressure. The 

 epiphyses may be displaced or bent, especially in the ribs, less frequently 

 in the long bones. The long bones and the pelvic bones may be bent 

 into a variety of forms (Fig. 491). Incomplete fractures are not infre- 

 quent. Complete fractures do not usually occur until the later stages of 

 the disease, when the bones have become more solid. In the head, the 



FIG. 491. RICKETS. 

 Showing irregular cssifk-ation and bending of the long bones. 



cranium may be unnaturally large for the size of the face ; the fontaneiles 

 and sutures may remain open; the bones may be soft, porous, and 

 hypera3rnic, while at their edges there may be rough, bony projections 

 beneath the pericranium. Sometimes, especially in the occipital bone, 

 there are rounded defects in the bone, filled only with a fibrous 

 membrane; this constitutes one of the forms of so-called Craniotabes 

 (Fig. 492). 



