INFLAMMATION. 425 



tion or necrosis. But how much is true of the " specificity " of such low organ- 

 isms, as regards malarial fever, recurrent fever, typhoid fever, syphilis, leprosy, 

 diphtheria, etc., is a question which to-day cannot be positively answered, as 

 the sources of mistake, both in experimental and microscopical research, are 

 too many and too little undej? our control. What the infecting germs of 

 measles, scarlet-fever, and small-pox are, we do not know. 



Secondary Changes. Among the disturbances of nutrition, 

 partly considered as inflammatory, partly unknown in their 

 origin, three deserve mentioning namely, the fatty, the pig- 

 mentary, and the waxy degeneration. 



Fatty Degeneration. As mentioned before (see page 155), the 

 fat-granules are directly produced from granules of bioplasson. 

 Every living tissue, in a physiological or pathological process, 

 may exhibit fat-granules, both in its free bioplasson bodies and 

 in the interstitial substances. In this latter, situation, also, the 

 fat originates from the bioplasson formations. In the myxoma- 

 tous and fibrous variety of connective tissue the fat is a normal 

 product, at least to a certain degree ; cartilage corpuscles often 

 exhibit fat granules and globules, even in middle-aged individ- 

 uals. In chronic inflammation of cartilage and bone, especially 

 in their ulcerative destruction, in caries, fat-granules are very 

 common occurrences in the plastids. In muscles, fat-granules 

 arise from a direct transformation of the sarcous elements : in 

 paralyzed and atrophied muscles, from want of exercise; in 

 typhoid fever ; in the muscle of the heart, either as an independ- 

 ent pathological process, or in connection with hypertrophy. In 

 higher degrees of fatty degeneration of the muscle of the heart, 

 nearly the whole organ, but principally the left ventricular 

 wall assumes a yellow color, and the tissue becomes quite brit- 

 tle. Most of the sarcous elements have been converted into 

 fat-granules, which slightly exceed the original sarcous elements 

 in size j they still remain interconnected, however, by delicate 

 filaments. In the ganglionic elements of nerve-tissue, fat-gran- 

 ules are often met with ; this always indicates a disturbance in 

 the intellectual, sensitive, or motor centers. I have seen fatty 

 degeneration of the axis-cylinders of nerves, resected for the 

 relief of neuralgia, caused by the so-called perineuritis i. e., 

 chronic inflammation of the external and internal perineurium. 

 In epithelia and endothelia fatty degeneration also occurs, reach- 

 ing its highest degree in the epithelia of the liver. Wedl has 

 demonstrated fatty degeneration even in the cement-substance 

 of epithelia perfectly healthy. A rare and sometimes intra- 



