Pathogenesis 445 



development in about forty-eight hours. They are at first 

 round bright globules, and later become grayish and opaque. 

 They measure i to 2 mm. in diameter and never become 

 confluent. They are difficult to pick up with the platinum 

 wire, tending to slide over the smooth surface of the medium. 



Vital Resistance. The organisms seem to possess little 

 vitality, their life in artificial culture being limited to a few 

 days. Frequent transplantation enabled Davis to carry 

 them on to the eleventh cultural generation. 



Pathogenesis. The organism is pathogenic for man 

 and certain monkeys (macacus), but not for the ordinary 

 laboratory animals. The organism can be found in large 

 numbers in both the genital and extragenital chancroidal 

 lesions, and usually in small numbers in the pus from chan- 

 croidal buboes. It has not been encountered elsewhere. 

 Lenglet* isolated the organism in pure culture, and by 

 inoculation with his cultures reproduced the lesions in man. 



*"Bull. Med.," 1898, p. 1051; "Ann. de Dermatol. et de Syph.," 

 1901, t. n. p. 209. 



