276 



THE MICROSCOPIST. 



pia mater. The cells of the sheath multiply, and numer- 

 ous gray nodules are produced around the vessel. 



Microscopically, Wagner describes fresh miliary tuber- 

 cle as consisting of one or more (from four to six gener- 

 ally) rounded follicles or nodules, each composed of a 



Vertical section through the pia mater and the contiguous portion of the cortex of 

 brain in tubercular meningitis, a, a. A larger vessel of the pia mater whose entire 

 sheath is intiaiumatorily infiltrated. 6,6. Lymph-spaces of the pia mater with com- 

 mencing tubercular proliferation of the endothelia. c. Miliary tubercle of the pia mater. 

 d. Outermost layer of cortex of brain infiltrated with round cells, e. Normal brain-sub- 

 stance. /,/. Proper cerebral vessels in a state of tuberculous degeneration. After RIND- 



FLEISCH. 



reticulum and cellular elements. The latter are free nu- 

 clei, cells like leucocytes with one or two nuclei, and in 

 the centre of the follicle one or more polynuclear giant 

 cells. The latter are granular and branching, with 20 to 

 100 rounded and comparatively large nuclei. In addition 

 there are cells of intermediate size, epithelial-like, rounded, 

 and finely granular. Tubercle always occupies the place 

 of normal tissue, which is either wasted or pushed aside 

 by it. 



There may be atrophy or necrosis of the elements of 

 tubercle, after which cornification may transform it into 

 a hard horny mass. Eesorption rarely occurs, but calci- 



