20 BOVINE PATHOLOGY. 



form o£ degeneration, the part affected becoming a mass 

 of substance of a cheese-like character, yellow in colour, 

 inelastic, and rather soft. Tuberculous deposits are very 

 liable to undergo this change, as also certain malignant 

 growths. 



Calcareous Change depends upon the deposition of 

 lime salts in the intercellular substance of a tissue, 

 whereby it assumes a gritty character and becomes opaque 

 and resistant. It occurs very frequently as a result of 

 excessive activity of the process which normally hardens 

 the costal and laryngeal cartilages of old animals, and is a 

 means by which deposits are rendered permanent and 

 prevented from absorption. 



These processes of degeneration take place normally 

 in certain parts of the body, and when they occur in 

 disease are either in excess in normal situations, or in 

 abnormal sites. The mucoid and colloid degenerations 

 tend to softening of tissue. Fatty degeneration places 

 the matter in that condition under which it is most 

 fit for removal. Caseous change tends rather to per- 

 manency, while calcification exhibits this to a still more 

 marked degree. The calcareous change generally as- 

 sumes the character of an infiltration, involving 

 intercellular tissues rather than the cellular elements 

 of a part, and resulting from the deposition of matter 

 from the blood instead of its production as a result of 

 change in the protoplasm of the cells. Fatty infiltra- 

 tion is very common, involving such organs as the liver 

 and muscles (especially the heart) in animals fattened for 

 slaughter. This proves prejudicial when the accumula- 

 tions of fat pressing upon the tissue elements of the 

 affected part impair their nutrition. Accumulations of fat 

 of this nature occur physiologically in the processes of 

 fattening, then the connective-tissue corpuscles are 

 affected, and this very frequently occurs also in disease. 



Pigmentary Infiltration especially affects the lungs 

 of old animals. 



Amyloid Infiltration has been observed in the liver, 

 and consists in the deposition from the blood of a starchy 



