194 



TUBERCULOSIS 



the seemiug predilection for the larger lobes to be due to 

 mechanical conditions. The writer has found, however, that 

 in certain herds that have been killed after the tuberculin test, 

 the primary and only lung lesions were in the ventral and 

 cephalic lobes. It is important to note that usually the bron- 

 chial glands are also involved. When the pleurae are affected 

 the lesions consist of nodules varying in size from that of a 

 millet seed to a large pea, sprinkled more or less thickly on 

 one or both of the visceral or parietal surfaces. These form 



Fig. 39. Pholograph of pleura showing small tuberculous nodules. 



the "pearl disease" Perlsucht of the German and the 

 "grape disease" of the English writers. If they become 

 confluent, large masses are found. 



Tuberculosis of the thoracic glands is very common and 

 usually accompanies lesions in the lungs; but the lungs may 

 be healthy and the glands involved. (See figures for location 

 of glands.) The primary lesions may be and often are found 

 in the lymphatic glands about the head. 



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