298 SPECIFIC MICRO-ORGANISMS 



rather difficult to stain and Gram-negative. Cultures are 

 obtained on ordinary agar smeared with fresh human or rabbit's 

 blood or upon a mixture of blood and agar. Hemoglobin seems 

 essential to growth. The bacillus is very sensitive to drying, 

 and its transmission would seem to occur largely through close 

 association, and the scattering of moist droplets of material 

 from the nose and mouth in sneezing, coughing and talking. 

 The cultures are toxic for rabbits and monkeys. The causal 

 relation of B. influenza to influenza is not as yet fully established. 

 Conditions resembling influenza very closely seem to be caused 

 by other organisms, such as the cocci. 



Bacillus (Bacterium) Chancri (Bacillus of Ducrey). Ducrey 

 in 1889 found a short bacillus in the soft venereal sore known 

 as chancroid, obtained it in pure culture and produced typical 

 lesions by inoculation in man. The organism is about 0.5X1.5^, 

 often growing in threads. It grows on a blood-agar mixture at 

 37 C. Material for culture should be obtained from an un- 

 broken pustule or from a chancroidal bubo, so as to avoid con- 

 taminating organisms. The bacillus possesses very little resist- 

 ance to drying or to germicides. Successful inoculation experi- 

 ments have been carried out on man, on monkeys and on cats. 

 Other organisms 1 appear to produce soft chancre in the absence 

 of the Ducrey bacillus in some cases. 



1 Herbst and Gatewood: Journ. A. M. A. t 1912, Vol. LVIII, pp. 189-191. 



