23 



all successive transplants grow more readily until the luxuriance 

 of the growth reaches a maximum. A similar delay in the appear- 

 ance of the primary growth has often been observed in certain 

 cultures of plague, dysentery, and other bacteria. 



I have not experienced the difficulty, which is mentioned by 

 some authors, in keeping cultures of Bacterium mallei alive. Pos- 

 sibly this is because the cultivations were made upon media of very 

 nearly the same reaction. Cultures isolated over nine months ago 

 are still alive. They have been transplanted upon glycerine agar 

 at intervals of about three months and kept in the ice chest. 



BIOCHEMICAL CHARACTERS (AT 35-37). 



-\-l Agar. 1 A moist, whitish, translucent streak with even edges 

 appears in twenty-four hours. The growth reaches its maximum 

 in about three days, when the edges become slightly crenated. The 

 growth is quite viscous when touched with the platinum needle. 

 There is no further change during nine or ten days. 



+1 agar with 3 per cent glycerin. The growth is slightly more 

 rapid than on +1 a g ar > an ^ the luxuriance of the growth increases 

 steadily for five to six days. Saprophytic cultures may spread over 

 the whole surface of a slant. The growth becomes smooth, shining, 

 light brown in color, and quite viscous. Some old cultures present 

 large, fan-like crenations along their edges. 



-\-l agar with 8 per cent sodium chloride. A scarcely visible 

 growth appears in twenty-four hours. In forty-eight hours a very 

 slight, dryish, granular growth may be seen by reflected light. 

 There is no further increase and the culture is found to be dead to 

 further transplantation after a few days. 



-\-l sugar-free bouillon. The growth occurs as a uniform cloudi- 

 ness. A viscous sediment collects during eight or nine days. No 

 indol is produced in ten days. 



1 per cent peptone (Witte's) solution. A faint turbidity, accom- 

 panied by the formation of a slight sediment is produced in twenty- 

 four hours, after which there is not much increase, ^"o indol is 

 produced in ten days. 



'The culture media was prepared according to the recommendations of 

 the American committee, excepting that the reaction to phenolpthalein 

 was adjusted by the addition of normal sodium hydroxide alone, -f-1 means 

 1 per cent acid .with phenolphthalein as an indicator. (See the Reports 

 and Papers of the American Public Health Association, 1898, 23, 60.) 



OF THE 



UNIVERSITY 



OF 

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