476 Veterinary Medicine. 



seats of tuberculosis, the lung, may in acute cases show a diffuse 

 miliary tuberculosis, a considerable part of a lobe or of several 

 lobes being congested, infiltrated, and filled with small individual 

 tubercles, grayish or transparent in the midst of the general red- 

 ness. A second form, often of old standing, is in the shape of 

 hard masses, often circumscribed or isolated, and easily felt when 

 the soft lung tissue is manipulated. They are respectively formed 

 by the local aggregation, and confluence of the small miliary 

 nodules and may vary in size from a pea to a mass of ten or 

 twelve inches in diameter. On section the miliary tubercle may 

 not yet show central caseation, but the larger ones do so as a 

 rule. The caseated nucleus may be soft, cheesy and somewhat 

 homogeneous ; it may be dry, granular and yellow, resembling 

 damp farina of maize ; it may be calcified in its outer portion and 

 invested by a firm fibrous envelope. The tubercle may be the seat 

 of general fibroid degeneration, constituting the pearl nodules 

 (perl-knoten) dense as cartilage and either with or without a soft 

 caseated centre ; it may show an agglomeration of nodules in all 

 stages from the early congested nodule to advanced caseation or 

 cretefaction, the whole embedded in a solid congested and infil- 

 trated tissue, largely fibroid. There may be extensive abscesses, 

 the seats of complex infections, having thick uneven walls, often 

 showing grape like tuberculous outgrowths, and containing thick, 

 caseo-purulent, viscous, granular, yellowish or greenish and 

 comparatively odorless contents : in other cases the abscesses 

 have burst into the bronchia, leaving vomices and with the new 

 resultant infections the contents have acquired an offensive putrid 

 odor ; finally, there may be extensive inflammatory infiltrations, 

 affecting lobules or lobes, and interspersed with tubercles in the 

 form of the early grayish or transparent nodule, or even more 

 advanced caseous or cretaceous centres. These latter serve to 

 distinguish the condition from broncho-pneumonia, the grayish 

 centres of which might suggest miliary tubercle. The broncho- 

 pneumonia, however, has the whitish centres confined to the 

 bronchioles and their terminal air sacs, and represent their thick- 

 ened walls and muco-fibrinous contents ; they do not show the 

 same tendency to caseation, nor necrosis of the tissue, nor to 

 caseation of the dependent lymph glands, and, above all, they do 

 not contain the bacillus tuberculosis. 



