TRANSITORY FATTY INFILTRATION. 365 



extent capable of action. This process therefore is 

 essentially different from necrobiosis, where the muscu- 

 lar fibres as such completely perish. Here we have a 

 purely interstitial formation of adipose tissue, ordinary 

 connective tissue becoming converted into adipose tissue, 

 and the term, fatty degeneration, which is so very liable 

 to be misunderstood, should be avoided. 



This form occurs pretty frequently, especially in the 

 heart, and may, when it attains a great extent, produce 

 considerable derangement in the motor power of the 

 muscular substance of this organ, but in pathological 

 importance it stands far below real fatty metamorphosis, 

 although this again in its outwardly visible results much 

 resembles it. The hearts described by the old anato- 

 mists as fatty were in a great measure only hearts infil- 

 trated with fat ; on the other hand, what is meant at 

 the present day when genuine fatty degeneration (meta- 

 morphosis) of the heart is spoken of, is not this obesity 

 of the heart, this interlarding of its fibres with fat-cells, 

 but rather a real transformation of its substance, going 

 on in the interior of the fibres (Fig. 23). In the latter 

 case the fat lies in, in the former between the primitive 

 fasciculi. 



The second series of processes consists in the transi- 

 tory accumulation of fat in certain organs, as we meet 

 with it in a typical form in digestion. When a fatty 

 substance has been eaten, and has passed into the state 

 of emulsion, we find that, when it has reached the 

 upper end of the jejunum, and to some extent even in 

 the duodenum, the villi of the mucous membrane be- 

 come whitish, clouded and thick, and more minute 

 examination shows, that they are filled with extremely 

 minute granules, much more minute than can be pro- 

 duced by .any artificial emulsion. These granules, 

 which are found even in the chyme, come in the first 



