DEGENERATIONS AND INFILTRATIONS. 273 



this fatty residue would accumulate within the cytoplasm. Fatty 

 foods would, of course, be little, if at all, utilized. 



This leads to the inference that one of the chief features in the 

 disturbed metabolism of the cell is an inability to bring about the 

 complete oxidations that normally take place in the cytoplasm, and 

 when we examine the conditions in which fatty degeneration occurs 

 we notice that a group of them are such as would involve a dimin- 

 ished amount of oxygen in the blood. This is manifest in cases of 

 anaemia, advanced phthisis, and poisoning with carbonic oxide, which 

 destroys the respiratory value of the haemoglobin. 



In the subacute and chronic toxic conditions e. (/., such cases of 

 poisoning by phosphorus or arsenic in which the patient survives 

 for a considerable time the blood probably contains a sufficiently 

 abundant supply of oxygen for the needs of the tissues. But intra- 

 cellular respiration is a complicated process ; not a simple and direct 

 burning of substances occasioned by their immediate conversion into 

 fully oxidized compounds when brought into relations with free 

 oxygen. The food-materials are split up within the cell into com- 

 pounds of simpler constitution, some of which receive a sufficient 

 amount of oxygen, from the original material of which they are 

 derivatives, to satisfy their affinities, and are, therefore, stable ; 

 while others are organic substances in a chemically reduced state, 

 which unite with the free oxygen that may be accessible. The oxi- 

 dation is not caused by the presence of free oxygen, but is an inci- 

 dent in the chemical changes carried on by the cell. 



In the toxic conditions leading to fatty degeneration this intra- 

 cellular oxidation is probably interfered with through the action of 

 the poisons upon the cytoplasm, and, as a result, the least easily 

 oxidizable substance, fat, remains as an unutilized residue. The 

 poisons at the same time probably interfere with the nutrition of the 

 cell, which draws upon its organized proteids for a supply of nitro- 

 gen, leaving again a remnant of unavailable fat. 



It is easily comprehensible that relative overwork may have the 

 same effect upon the cell as relative innutrition. The fatty degen- 

 eration of the heart-muscle as the result of stenosis or of valvular 

 insufficiency at one of its orifices would, therefore, be explained as 

 an example of a lack of balance between the supply and consump- 

 tion of food in the economy of the cardiac cells. Relative overwork 

 of the heart is also one of the effects of marked anaemia. The 

 anaemic condition involves a diminished supply of oxygen, from 



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