35 6 Leprosy 



The colonies that form upon agar-agar are much like 

 those described by Bordoni-Uffredozzi, and appear as 

 isolated, grayish, rounded flakes, thicker in the center than 

 at the edges, and characterized by an irregular serrated 

 border from which a fine irregular network extends upon the 

 medium. These projections consist of bundles of the bacilli. 



When a transfer was made from one of these colonies 

 to fresh media, the growth became apparent in a few days 

 and assumed a band-like form, with a plateau-like elevation 

 in the center. 



The bacillus thus isolated grew with moderate rapidity 

 upon all the ordinary culture media except potato. Upon 

 blood-serum the growth was more luxuriant and fluid 

 than upon the solid media. Upon coagulated serum the 

 growth was somewhat dry and elevated, and was frequently 

 so loosely attached to the surface of the medium as to 

 be readily lifted up by the platinum wire. 



The growth was especially luxuriant upon sheep's blood- 

 serum to which 5 per cent, of glycerin was added. The 

 growth upon the lyoffler mixture was also luxuriant. 



Upon agar-agar the growth is more meager; it is more 

 luxuriant upon glycerin agar-agar than upon plain agar- 

 agar, the bacterial mass appearing grayish and flatter than 

 upon blood-serum. The growth never extends to the 

 water of condensation to form a floating layer. 



The bacillus develops well upon gelatin after it has grown 

 artificially for a number of generations and become accus- 

 tomed to a saprophytic existence. Upon the surface of gela- 

 tin the growth is, in general, similar to that upon agar-agar. 

 In puncture cultures most of the growth occurs upon the 

 surface to form a whitish, grayish, or yellowish wrinkled 

 layer. Below the surface of the gelatin the growth occurs as 

 a thick, granular column. The medium is not liquefied. 



In bouillon growth occurs only at the bottom of the tube 

 in the form of a powdery sediment. 



Ducrey seems to have cultivated the lepra bacillus in 

 grape-sugar, agar, and in bouillon in -vacua. His results 

 need confirmation. 



Rost * finds it easy to isolate and cultivate the lepra bacil- 

 lus upon media free from sodium chloride. The technic of his 

 method is thus described by Rudolphf: "Small lumps of 



* " Brit. Med. Jour.," Feb. 22, 1905, and " Indian Med. Gazette," 1905. 

 t" Medicine," Mar., 1905, p. 175. 



