MICROSCOPIC APPEARANCE OF TUBERCLES. 291 



exist for the description of tlie macroscopic appearance 

 of these uodules, yet it is very rarely that any condition 

 other than that due to the fusion together of several of 

 these minute foci can be detected by the naked eye. 



The miliary tubercles are of a pale gray color, with a 

 white centre, are slightly elevated above the surface of 

 the tissue in which they exist, and, as stated, vary con- 

 siderably in dimensions, usually appearing as points 

 which range in size from that of a pin-point to that of 

 a pin-head. They are not only located upon the surface 

 of the organs, but are distributed through the depths of 

 the tissues. To the touch they sometimes present noth- 

 ing characteristic, but may frequently, when closely 

 packed together in large numbers, give a mealy or 

 sandy sensation to the fingers. Stained sections of these 

 miliary tubercles present a distinctly characteristic 

 appearance, and the disease may be diagnosticated by 

 these histological changes alone, though the crucial test 

 in the diagnosis is the finding of tubercle bacilli in these 

 nodules. 



Microscopic Appearance of Miliary Tuber- 

 cles. — The simple miliary tubercles under a low 

 magnifying power of the microscope present somewhat 

 the folio wing appearance: there is a central pale area, 

 evidently composed of necrotic tissue because of its in- 

 capacity for taking up the nuclear stains commonly 

 employed. Scattered here and there through this ne- 

 crotic area may be seen granular masses irregular in 

 size and shape; they take up the stains employed, and 

 are evidently the fragments of cell-nuclei in the course 

 of destruction. Through the necrotic area may here 

 and there be seen irregular lines, bands, or ridges, the 

 remains of tissues not yet completely destroyed by the 



