I 7 O BACTE RIOLOGY. 



days in the fuchsine solution employed in the method of 

 Erhlich (p. 163) ; or the solution may be warmed, and in 

 the case of cover-glasses, even raised to boiling-point. 

 They are then decolorised with nitric acid, and after- 

 stained with methylene-blue. 



Bacillus leprae, Hansen. Fine slender rods, 

 4 6 JJL long, and less than i //, wide, occasionally 

 pointed at both ends, some clearly motile, and 

 others not. Many possess bright oval spores, and 

 others have a beaded appearance. They have been 

 cultivated artificially on blood-serum and alkaline 

 meat extract. Inoculation experiments on monkeys 

 and other animals have failed to produce the dis- 

 ease ; though in cats and rabbits there have been 

 indications of success.* The bacilli occur in 

 enormous numbers 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, etc.f 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. 



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

 t Thin, Med.-Chir. Trans. Land., 1883 ; Brit. Med. Journal, 

 No. 1229, 1884, and Steven, Brit. Med. Journal, No. 1281, 1885. 



