DEGENERATIONS AND INFILTRATIONS. 



269 



of toxic conditions that are not accompanied by rise of tempera- 

 ture. 



In all the foregoing cases the cause is of an acute nature, acting 

 rapidly on the cells. If that action be moderate in degree and per- 

 sistent, the albuminoid degeneration passes into fatty degeneration. 

 Hence the latter has been called " chronic pareuchymatous inflam- 

 mation." 



But fatty degeneration is not always preceded by albuminoid 

 degeneration. It is found widely distributed in the cells of the 

 body in anaemia (Fig. 247), leucaBmia, and phthisis, and in many 



FIG. 247. 



Localized fatty degeneration of the cardiac muscle in a case of pernicious anaemia. (Birch- 

 Hirschfeld.) The three or four fibres at the bottom of the figure are nearly, if not quite, 

 normal. The rest of the fibres are the seat of an extensive fatty degeneration, resulting 

 in a complete obliteration of the normal striations of the contractile substance. Section 

 of the fresh, unstained muscle. The nuclei, being unstained, are but faintly visible in 

 such sections, and are not represented. 



toxic conditions that are of a subacute or chronic character. In a 

 more localized form it follows those diseases of the bloodvessels 

 which interfere with a normally abundant supply of blood to the 

 parts in which they are distributed. It appears, again, in parts the 

 functional activity of which is markedly increased without a corre- 

 sponding increase in the nutrient supply. For example, in stenosis 

 of an orifice of the heart, when extra work is thrown on the cardiac 

 muscle and the nutrient supply is insufficient to permit of hyper- 

 trophy, the muscle-cells suffer fatty degeneration, and the conse- 

 quent weakening of its walls results in dilatation of that particular 

 cavity which is subjected to the difficult task of urging the blood 

 through the narrowed orifice. 



If we examine these various conditions with a view to determin- 

 ing their effects upon the cells, we shall find that they have one 

 common feature. There is in all of them a lack of balance between 

 the nutrient supply of which the cells can avail themselves and 



