THE SKELETON 71 



physicians shows that any continued pressure, such as that of a 

 tumor, will cause the absorption and disappearance of bone almost 

 quicker than that of any other tissue; and the same is true of any 

 other continued pressure. Moreover, during life the bones are 

 eminently plastic; under abnormal pressures they are found to 

 assume abnormal shapes quickly, being absorbed and disappear- 

 ing at points where the pressure is most powerful, and increasing 

 at other points; tight lacing may in this way produce a permanent 

 distortion of the ribs. 



When a bone is fractured a surgeon should be called in as soon 

 as possible, for once inflammation has set in and the parts have be- 

 come swollen it is much more difficult to place the broken ends of 

 the bone together in their proper position than before this has 

 occurred. Once the bones are replaced they must be held in posi- 

 tion by splints or bandages, or the muscles attached to them will 

 soon displace them again. With rest, in young and healthy per- 

 sons complete union will commonly occur in three or four weeks; 

 but in old persons the process of healing is slower and is apt to be 

 imperfect. 



Articulations. The bones of the skeleton are joined together in 

 very various ways; sometimes so as to admit of no movement at 

 all between them; in other cases so as to permit only a limited 

 range or variety of movement ; and elsewhere so as to allow of very 

 free movement in many directions. All kinds of unions between 

 bones are called articulations. 



Of articulations permitting no movements, those which unite 

 the majority of the cranial bones afford a good example. Except 

 the lower jaw, and certain tiny bones inside the temporal bone be- 

 longing to the organ of hearing, all the skull-bones are immovably, 

 joined together. This union in most cases occurs by means of 

 toothed edges which fit into one another and form jagged lines of 

 union known as sutures. Some of these can be well seen in Fig. 25 

 between the frontal and parietal bones (coronal suture) and be- 

 tween the parietal and occipital bones (tambdoidal suture); while 

 another lies along the middle line in the top of the crown between 

 the two parietal bones, and is known as the sagittal suture. In new- 

 born children where the sagittal meets the coronal and lambdoidal 

 sutures there are large spaces not yet covered in by the neighboring 

 bones, which subsequently extend over them. These openings 



