PART 11.3 Nature of the Lumps of Black Substance. 367 



As there is less disturbance of the surrounding tissues where the dark masses 

 are found enclosed in minute cysts, they will present fewer complications, and are 

 therefore more instructive than the large tumours described in connection with the 

 last specimen, with all the extensive alterations which had taken place in connection 

 with them ; in other words, the significance of the presence of the larger masses 

 will become more evident after examination of the smaller ones which are found 

 under less complicated conditions. 



Whilst describing specimens of the pale variety. Chapter III (Specimen IV 

 page 351), and Specimens II and III (pages 362, 363) of the dark variety of the 

 disease in the last chapter, attention has been drawn to the fact, that certain of 

 the fat lobules in the subcutaneous tissues had undergone some alteration ; whereas 

 other, immediately adjoining, fat lobules were apparently in the normal state or 

 only altered to a trifling extent. Some of these altered lobules which have been 

 found in preparations affected with the dark variety of the disease have contained 

 dark granules. The accompanying woodcut of a dissection under a low power of a 

 little group of this kind will more clearly convey our meaning. A little of the 

 subcutaneous tissue from over the ankle joint of Specimen 

 II (page 362) was removed and spread out under the dis- 

 secting microscope for the purpose of examining a minute 

 dark speck in the midst of what seemed to be normal 



adipose tissue, which seemed likely to prove to be the 



Fig. 11. — Three encysted masses 

 peculiar dark substance found in connection with the malady, of altered adipose and con- 



enclosed in a capsule. This encysted little mass was lying nective tissue. The centre 



. one torn open and showing 



between two somewhat hardened, otherwise normal, healthy, the characteristic black 



encysted aggregations of fat, as delineated in the engrav- granules... x 6. 



ing (Fig. 11), in which the lining membrane surrounding the dark material is repre- 

 sented as torn open. This capsule was, however, more dense than the capsules 

 surrounding the ordinary fat masses, although it resembled them in general appear- 

 ance. Microscopically it consisted of connective tissue, but with a smaller proportion 

 of elastic fibres than that in the normal capsules. It was easily teased out. The 

 material enclosed by the capsule consisted of an aggregation of smooth, black, ova- 

 like particles, each of which was contained in a separate fibrous capsule similar in 

 structure to the general investing capsule, so that the bodies were, although closely 

 aggregated, quite distinct from one another. The black matter could be readily 

 pressed out from the capsules, leaving the latter more or less empty. 



Whatever may be the nature of the agent which determined the formation of 

 this minute saccule of dark granules in the midst of saccules of fat cells, it can 

 scarcely be doubted that it must be essentially identical in character with the agent 

 which determined the formation of the large nodular masses in the midst of the 

 bones and areolar tissue of the same preparation — the darkened material being in 

 the two cases of precisely similar composition. 



