138 TUBEKCLE. 



contain a single round nucleus, not of great relative size, very 

 lustrous, usually eccentric in position, though seldom causing 

 any lateral protuberance on the surface of the cell. In some of 

 the cells, we find two, three, or more such nuclei, which undoubt- 

 edly originate by fission of the original solitary nucleus ; for we 

 also meet with the intermediate stages of the process in the 

 form of elongated, biscuit- (hourglass-) shaped, and even more 

 deeply constricted nuclei. This fission of the nucleus is to Ije 

 regarded as preparatory to an endogenous production of small 

 cells, utterly unlike those just described ; the latter process indeed 

 is not always carried through ; so that even in the oldest tuber- 

 cles, we may occasionally meet with multinuclear giant-cells 

 i^Langlians), 



2. (Fig. 43) — Represents the second form of corpuscular 

 elements, such as may be isolated in greatest number by teazino- 

 out a miliary tubercle. They have nothing in common with 

 those just described save their lustrous, dark-bordered nuclei. In 

 all other points they differ from them, and chiefly in their size, 

 which is far smaller, and which enables them during their endo- 

 genous develoj^ment to exist three and more together in one of 

 the parent-cells ; they differ moreover by the transparent, homo- 

 geneous, and feebly-refracting character of their protoplasm ; 

 the exact opposite of these properties being especially character- 

 istic of the larger cells. It is the last-named of these dis- 

 tinctions which enables us to recognise the young cell in the 

 interior of its parent. The appearance of bright areolae round 

 the nuclei of the latter coincides with the beginnings of endo- 

 genous production ; we may regard the latter as complete when 

 the bright area is marked off by a sharp line from the sur- 

 rounding finely-granular and highly-refractive substance of 

 the parent-cell. This phenomenon is illustrated in fig. 43, 

 3, representing appearances which are very commonly ob- 

 served. 



These cells compose the main bulk of the miliary tubercle. 

 What remains after their removal by pencilling and repeated 

 washing, is the finely fibrous network represented in fig 43, 4, 

 to which we shall have to refer hereafter. 



§ 115. Let us now pass on to decide the second question, 

 that concerning the mode of origin and development of the 

 miliarv tubercles. We may expect a priori to find that this 



