212 THE DISEASES AND DISOEDERS OF THE OX. 



in animals in which the disease has been artificially produced, 

 either by inoculation, or feeding, with tubercular matter in the 

 case of cats, guinea-pigs, rabbits, fowls, and rats. They are also 

 found in the blood in acute miliary tuberculosis of man. 



Many deposits which have been but newly made do not show the 

 presence of the tubercle-bacilli ; but it is possible, of course, that 

 they or their spores in such cases may have escaped detection. 

 These tubercle-bacilli are different from other bacilli; but as 

 regards their chemical constitution they are not unlike the bacilli 

 of leprosy. If these bacilli are found in the sputum of a 

 patient, the presence of the disease may be said to be 



- ' > 



R 



Fig. 20. 



From a preparation of human tuberculous sputum, stained after the Ehrlich- 

 Weigert method. The nuclei in the specimen were stained blue, the tubercle- 

 bacilli pink. Magnifying power 700. After Klein. 



established beyond all possibility of doubt. Some of the bacilli 

 look smooth and homogeneous, while others are more beaded in 

 appearance. 



The bacilli are most numerous in the caseous masses found 

 in the lungs of affected oxen. They do not move about, and they 

 are said to contain frequently bright oval granules which may 

 be spores. It is very probably owing to the presence of these 

 spores, if spores they be, that human sputum and other tubercular 

 matter retains its virulence, even after drying. It has been 

 thought that such tubercular matter may dry and crumble, so 

 that the germs of the disease may be driven about by the wind. 



