266 BACTERIOLOGY. 



appearance (Fig. 102). Spore-formation has been 

 described. They have been cultivated artificially 

 on blood serum and alkaline meat extract. In- 

 oculation experiments on monkeys and other 

 animals have failed to produce the disease ; though 

 in cats and rabbits there have been indications 

 of success.* The bacilli occur in enormous num- 

 bers in tubercular leprosy in the nodules of the 

 skin (Plate XXIII., Figs, i and 2), and of the 

 mucous membrane of the mouth, palate, larynx, 



FIG. 102. LEPROSY BACILLI FROM A SECTION OF SKIN, x 1200. 



etc.")" They occur also in the liver, spleen, testicles, 

 lymphatic glands, and kidneys (Plate XX., Fig. 2) ; 

 and in the interstitial tissue of the nerves in 

 anaesthetic leprosy. They probably spread by 

 the lymphatics, and are not found in the blood. 

 In their behaviour to staining reactions they are 

 similar to the bacillus of tubercle, except that they 

 stain much more readily. 



METHODS OF STAINING THE BACILLUS OF LEPROSY. 



Cover-glass preparations may be made in the ordinary 

 way, or by a special method, which consists in clamping a 

 nodule with a pile-clamp, until a state of anaemia of the 

 tissue is produced. On pricking with a needle or sharp 

 knife a drop of clear fluid exudes, from which cover-glass 



*Damsch, Virchow* s Archiv, Bd. 92, Heft i. 

 tThin, Med. Chir. Trans. Lond., 1883; Brit. Med. Journal, 

 No. 129, 1884, and Steven, Brit. Med. Journal, No. 1281, 1885. 



