404 Chancroid 



no relation between the cells and the bacilli. As a rule, they are 

 free, sometimes they are inclosed in leukocytes. The bacilli are not 

 motile, have no flagella and do not form spores. 



Staining. The organisms are somewhat difficult to stain, as they 

 do not retain the color well, giving it up quickly when washed. 

 They do not stain by Gram's method. 



Cultivation. The first successful isolation and cultivation of the 

 organism seems to have been by Benzancon, Griffon and Le Sours* 

 upon a culture-medium consisting of rabbits' blood i part, and agar- 

 agar 2 parts. Davis f has been equally successful in cultivating the 

 organism upon this medium. His method was as follows: 



"Tubes of 2 per cent, agar, reaction +1.5, were melted and 

 mixed with fresh rabbits' blood drawn under aseptic precautions, 



Fig. 146. Smear of pus of chancroid of penis stained with carbol-fuchsin 

 and briefly decolorized by alcohol. X 1500 (Davis). (Photomicrograph by 

 Mr. L. S. Brown.) 



in the proportion of two-thirds agar to one-third blood, and slanted 

 while in a fluid state. At a later period tubes of rabbits' blood-serum 

 uncoagulated, also rabbits' blood bouillon, one-third blood to two- 

 thirds bouillon, were used, and gave equally satisfactory results. 

 By employing small tubes of freshly drawn human blood pure cul- 

 tures were obtained in several instances from genital lesions, direct, 

 without any special cleansing of the ulcerated surface. This, I 

 believe, is the best medium for obtaining cultures from a source open 

 to contamination, the fresh blood apparently inhibiting to a certain 

 extent the growth of extraneous organisms." 



No growth takes place upon ordinary culture-media under either 

 aerobic or anaerobic conditions. 



Cultures are best obtained by puncturing an unopened bubo with 

 a sterile needle and planting the pus directly and immediately upon 

 the special medium which should have been warmed in the incubator 



*"Ann. de Dermat. et de Syphilog.," 1901, n, p. i. 

 t Loc. cit. 



