IN SUSCEPTIBLE ANIMALS. 409 



by Davaine (1872), which he induced in the first instance by inject- 

 ing putrid ox blood into rabbits, was due to the same pathogenic ba- 

 cillus. The writer obtained this bacillus (1887) in Cuba from the 

 blood of rabbits inoculated with liver tissue taken from, a yellow- 

 fever cadaver and kept for forty-eight hours in an antiseptic wrap- 

 ping. The name which we have adopted is that proposed by Hueppe 

 for the form of septicaemia to which it gives rise "Septikamia 

 hamorrhagica. " 



Morphology. Short bacilli with rounded ends, from 0.6 to 0.7 

 /* in diameter and about 1.4 ^ long; sometimes united in pairs, or 

 in chains of three or four elements. In stained preparations the ex- 

 tremities are usually stained, while the central portion of the rod 

 remains unstained. This " end staining" causes the rods to present 

 the appearance of diplococci when examined with a comparatively 

 low power, and some of the earlier observers described the microor- 

 ganism under consideration as a micrococcus. It is quickly stained 

 by the aniline colors usually employed, but loses its color when 

 treated by Gram's method. 



Biological Characters. A non-motile, aerobic, non-liquefy- 

 ing bacillus. Does not form spores. Grows in various culture media 

 at the room temperature, but more rapidly at 35 to 37 C. the 

 lowest temperature at which development occurs is about 13 C. 

 Although this is an aerobic bacillus and a certain amount of oxygen 

 is necessary for its development, it appears to grow better when the 

 amount is somewhat restricted than it does on the surface of nutrient 

 media. 



Upon gelatin plates, at the end of two or three days, small, 

 white colonies are developed upon or near the surface ; these are 

 finely granular and spherical, with a more or less irregular outline, 

 and by transmitted light have a yellowish color ; later the central 

 portion of the colonies is of a yellowish-brown color and is sur- 

 rounded by a transparent peripheral zone. The superficial colonies 

 are commonly smaller than those which develop a little below the 

 surface of the gelatin. In stick cultures in nutrient gelatin the 

 growth upon the surface consists of a thin, whitish layer in the 

 vicinity of the point of puncture, having an irregular, jagged out- 

 line sometimes there is no development upon the surface ; along 

 the line of puncture the growth consists of rather transparent, dis- 

 crete or confluent colonies. In streak cultures upon nutrient agar, 

 or gelatin, or blood serum the growth is limited to the immediate 

 vicinity of the line of inoculation, and consists of finely granular, 

 semi-transparent colonies, which form a thin, grayish-white layer 

 with irregular, somewhat thickened margins. Upon potato no de- 

 velopment occurs, as a rule, at the room temperature, but in the in- 

 33 



