CALCIFICATION AND OSSIFICATION OF ARTERIES. 407 



because it takes up lime into its intercellular substance 

 and has stellate cells present in it ; it may in spite 

 of all this be nothing more than calcified connective 

 tissue. When we speak of pathological ossification, we 

 always presuppose that the mass which ossifies has been 

 called into existence by an active process, an irritation, 

 and not that a previously existing tissue assumes the 

 form of bone, by absorbing calcareous salts. We have 

 therefore calcifications and ossifications in the vessels. 

 In ancient times everything was called ossification. 

 Many of the more recent observers have denied that it 

 ever does occur in vessels. Ossification does however 

 really occur, but so does mere calcification, or, as I will 

 briefly term it, petrifaction. The latter is compara- 

 tively more frequent in the peripheral arteries, so that 

 the condition which is generally regarded as a special 

 criterion of the atheromatous process and in which the 

 radial artery is felt to be hard and calcareous, and the 

 femoral or popliteal is perceived to have hard and rigid 

 walls, is no proof at all that the process is an atheroma- 

 tous one. Very frequently this induration has its seat 

 in the middle coat. In this case the calcification really 

 invades the muscular elements, so that the fibre-cells 

 of the circular-fibre coat are transformed into calcareous 

 spindle-shaped bodies. The calcareous matter may in 

 these cases also invade the neighbouring parts, but the 

 internal coat may possibly remain quite unaltered. This 

 is a process therefore, which differs more from what is 

 termed the atheromatous process than periostitis from 

 ostitis. This species of calcification has no necessary 

 connection whatever with an inflammation of the artery , 

 it occurs most commonly in cases where there is a ten- 

 dency to calcifications generally, and where calcareous 

 salts are set free at other points in the economy and cir- 

 culate with the juices. This much at least can with cer- 



