412 RETROGRESSIVE CHANGES 



basis, as follows: When a local acid intoxication of a cell occurs, 

 some of the proteins will swell and others will precipitate, resulting 

 respectively in the swelling and cloudiness of the cells characteristic 

 of cloudy swelhng; but at the same time the emulsifying capacity of 

 these proteins will be impaired, permitting the coalescence of the fat 

 droplets and the resulting picture will be that of fatty degeneration. 

 Summary .^ — Fatty metamorphosis involves changes of two kinds. 

 First, infiltration of fat, which occurs when the oxidative power of 

 the cells is decreased, so that fat is not destroyed, but is accumulated 

 from the blood under the influence of the hpase of the cells; if there 

 is not any serious injury to the cells, the histological changes consist 

 in the accumulation of one or a few large droplets of fat in each cell, 

 constituting the condition known anatomically as ''fatty infiltration." 

 This occurs, pathologically, chiefly in the Hver. If at the same time 

 the cytoplasm is disintegrated through autolylic changes, the fat- 

 droplets do not fuse, but remain as small, more or less discrete, fat 

 granules among the granules of cell debris, constituting the micro- 

 scopic picture of "fatty degeneration"; this condition occurs particu- 

 larly in the heart and hver. 



Second, each cell contains a large amount of fat and hpoids (5-25 

 per cent, of its dry weight), which is so combined that it cannot be 

 detected microscopically; this may be hberated during the autolytic 

 processes and colloidal changes of cell disintegration and become 

 visible, constituting a macroscopical and microscopical degeneration, 

 but without any actual increase in fat — this condition occurs particu- 

 larly in the kidney and nervous system. Third, a combination of 

 both of the above processes — infiltration of fat and liberation of 

 masked intracellular fat — may occur simultaneously in an organ. *^ 

 Fourth, in certain cells, especially in the kidney, adrenal, ovary and 

 some tumors, there may be a great increase in the lipoids of the cell, 

 ''lipoidal degeneration," and especially of cholesterol esters and free 

 cholesterol, part of which is infiltrated and part set free from com- 

 bination in the cytoplasm. 



PROCESSES RELATED TO FATTY METAMORPHOSIS 

 ADIPOCERE 



This apparent transformation of the substance of dead bodies into 

 a wax-like material was for a long time looked upon as evidence of a 

 transformation of protein into fat, but in the light of more recent in- 

 vestigations this view can hardly be held. Adipocere is the product 

 of a process that occurs particularly in bodies buried in very wet 



^' The above conception of the processes involved in fatty metamorphosis is 

 more fully discussed by the writer in other publications (Jour. Amer. Med. .\ssoc., 

 1902 (38), 220; ibid., 1906 (46;, 341). Ribbert (Deut. med. Woch. 1903 (29), 

 793) has also advanced a similar explanation for the morphological differences 

 between fatty "degeneration" and "infiltration," i. e., that the degenerative 

 changes are independent of fatty accumulation. 



