400 RETROGRESSIVE CHANGES 



storehouses. Furthermore, it was found that animals stai*ved to an 

 extremely low fat content do not develop the typical fatty liver of 

 phosphorus-poisoning:, a fact which Lebedeff had already noted in a 

 case of phosphorus-poisoning in an emaciated patient. Of similar 

 sigiiiticance is the fact that in fatty human livers the iodin number, 

 normally high, falls as the amount of fat increases until it is ap- 

 proximately that of adipose connective tissue.® Therefore, it seems 

 evident that the fat accumulating in the liver during fatty degenera- 

 tion is not derived, as Virchow thought, through a transformation of 

 cell proteins into fat, hut rather is an infiltrated fat brought in the 

 blood from the fat deposits of the body to the disintegrating organ. 

 This work has since been corroborated and extended by many ob- 

 servers, and its correctness can now hardly be questioned.' "Fatty 

 degeneration," therefore, differs from "fatty infiltration" chietiy in 

 the fact that in the former the process is associated with serious in- 

 jury 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 nonnal condition whenever the fat is removed.* 



Fatty "Degeneration" without Infiltration. — By showing that 

 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 analj^sis shows to be present. This 

 is particularly true of the kidney. Thus, the amount of fat and 

 lipoids, or lipins (to adopt the more comprehensive term recom- 

 mended by Rosenbloom and Gies ^ to include neutral fats, fatty acids, 

 soaps, lipoids, and their compounds), present in normal kidneys (dog) 

 was found to vary between 18.5 per cent, and 29.12 per cent, of the 

 dry weight, the average being 21.8 per cent. ; whereas, after producing 

 a typical "fatty degeneration" by means of phosphorus and other 

 poisons, the lipin content was still found to be between 16.9 per cent, 

 and 22.6 per cent.^" In all instances the amount of lipins in kidneys 



fi Leathos, Lanect, Feb. 27, 1000; Hartley and IMavrojiordato, Jour. Patli. and 

 Bact., 1008 (12), 371; Jaekson and Peare'e, .Tour. Kxp! ^led.. 1007 (0), 57S. 



7 Sehwalbe (Verli. der Deut. Path. Cesell., 1003 (0). 71) claims tliat in a sim- 

 ilar way iodin eomjiounds of fat can lie demonstrated to lie Iransjiorted into tlie 

 fatt}" organs. Tlis analyses were merely qualitative, and hy (|uantitative deter- 

 minations I was unable to corroborate his conclusions (Zeit. f. plivsiol. Chem., 

 1905 (45), 412). 



8 A strikinfT proof of the lack of injury associated Avitli fatty in(iltra(ion is 

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

 in which it may be diOicult to find, microscopically, any cell cytojdasm Ixn-ause 

 of the fat, the tissue looking like fatty areolar tissue; and yet there may be no 

 clinical evidence wliatevcr that tlie lix'cr function has be(Mi im])aire(I i)y tlie 

 jirocess. 



!> Bioclicm. I'.iillctiii, 1011 (1), -A. 



10 Concerning the normal intracellular fats see introductory chapter. 



