PATHOLOGICAL FAT ACCUMULATION 335 



quantities of these foreign fats. By starving again for a few 

 days the foreign fat was removed from the liver, leaving still a 

 large amount in the other storehouses, and the animals were then 

 poisoned with phosphorus or other poisons that cause a typical 

 fatty degeneration of the liver and other viscera. When the 

 fat was extracted from the fatty liver of these animals, it was 

 found that the new fat that had appeared in the liver during 

 the process was not normal dog fat (which it should have been 

 if formed by degeneration of the cell proteids), but was, in part, 

 of the same type as the foreign fat which the animals had deposited 

 in their subcutaneous tissues and other fat storehouses. Further- 

 more, it was found that animals starved to an extremely low 

 fat content do not develop the typical fatty liver of phosphorus- 

 poisoning, a fact which Lebedeif had already noted in a case of 

 phosphorus-poisoning in an emaciated patient. Therefore, it 

 seemed evident that the fat accumulating in the liver during fatty 

 degeneration is not derived, as Virchow thought, through a trans- 

 formation of cell proteids into fat, but rather is an infiltrated fat 

 brought in the blood from the fat deposits of the body to the disin- 

 tegrating organ. This work has since been corroborated and 

 extended by many observers, and its correctness can now hardly 

 be questioned. 1 " Fatty degeneration," therefore, differs from 

 " fatty infiltration " chiefly in the fact that in the former the 

 process is associated with serious injury to the cell, caused by 

 the action of toxins or loss of nutrition, while in the latter the 

 cell is not seriously injured and is capable of returning to its 

 normal condition whenever the fat is removed. 2 



Fatty " Degeneration " without Infiltration. By 

 showing that the new fat in fatty livers is infiltrated fat, 

 Rosenfeld did not entirely clear up the subject, for, in the 

 course of his analyses of organs that were macro- or micro- 

 scopically the seat of fatty degeneration, he found that there is 

 not always any correspondence between the amount of fat that 

 seems to be present, as determined by microscopic methods, and 

 the amount that chemical analysis shows to be present. This 



^chwalbe (Verb, der Deut. Path. Gesell., 1903 (6), 71) claims that in a 

 similar way iodin compounds of fat can be demonstrated to be transported into 

 the fatty organs. His analyses were merely qualitative, and by quantitative 

 determinations I was unable to corroborate his results (Zeit. f. physiol. Chem., 

 1905 (45), 412). 



2 A striking proof of the lack of injury associated with fatty infiltration is 

 shown by the fatty infiltration frequently seen in the liver, especially of alco- 

 holics, in which it may be difficult to find, microscopically, any cell cytoplasm 

 because of the fat, the tissue looking like fatty areolar tissue ; and yet there 

 may be no clinical evidence whatever that the liver function has been 

 impaired by the process. 



