ARTERITIS. 327 



faces of pericardium often look as if the two layers had rubbed 

 together, while the more or less marked deposit of fibrin was 

 still in a soft plastic condition, giving them a rough, ragged, 

 or hairy appearance, suggesting the term "cor villosum." 



The parietal and visceral layers may become agglutinated, 

 constituting what is known as adherent pericardium, which 

 may lead to hypertrophy of the heart, by reason of the in- 

 creased work thus imposed upon it. 



Sclerotic areas, known as white spots, or milk-spots, are 

 probably the result of a chronic localized inflammation ; they 

 are noted in about 50 per cent, of all post-mortems. They 

 may be quite small, or large enough to cover the anterior sur- 

 face of the heart. They occur most frequently on the right 

 ventricle, next on the left ventricle, near the apex, and also 

 on the posterior surface of the heart, near its base. They are 

 formed simply of dense connective tissue, covered by endothe- 

 lium. Their exact significance is not fully understood. 



THE BLOODVESSELS. 



DEGENERATIONS. 



Fatty degeneration : Not infrequently there are seen in the 

 aorta and other parts of the arterial system yellow spots or 

 streaks slightly raised above the internal surface ; under the 

 microscope it is found that the endothelial cells of the intima 

 have undergone fatty degeneration. The degeneration may 

 involve also the muscle-cells of the media. The affected areas 

 may soften and small superficial erosions result. 



Calcareous infiltration most frequently affects the middle 

 coat of the artery, occurring by preference in vessels of me- 

 dium size. The greatly increased rigidity of the radials, often 

 noted clinically, is generally due to this cause. 



Amyloid degeneration usually begins in the capillary walls 

 of the organ affected. The entire wall is involved. 



ARTERITIS. 



Acute inflammation of the walls of an avtery, independent of 

 any neighboring inflammatory process, is very rare. 



