DESCmPTION OF PLATE XII. 

 Tubercular Mammitis. 



Fig. 1. — From a section of the udder of a milch cow. The tubercular deposit 

 is seen to invade the lobules of the gland. Lobules comparatively healthy 

 are marked off, more or less sharply, from the diseased ones in which the 

 new growth in its progress compresses and obliterates the alveoli. Stained 

 by the Ziehl-Neelsen method and with methylene-blue. x 50. 



Fig. 2. — Part of the same preparation. On the right of the section part of a 

 healthy lobule is seen. On the left a lobule is invaded by tubercular new 

 growth composed of round cells, epithelioid cells and typical giant cells. 

 Tubercle bacilli can be seen both singly and collected in groups. They 

 are found in and between the cells, and in the interior of giant cells. 

 Bacilli may be seen between the cells lining an alveolus and projecting 

 into its l^men. x 800. 



