234 BACILLI OF THE HEMORRHAGIC SEPTICEMIA GROUP 



Plague Bacilli in the Blood. It appears that plague in rats generally 

 leads to an early true septicemia, that is, to an invasion of the blood 

 and a multiplication of the infecting bacilli. The Indian investigators 

 in experimental rat inoculation have found as many as 1,000,000,000 

 bacilli per cubic centimeter of blood. This exceptional figure was, 

 however, found only twice; other figures were as low as 10 to 100 per 

 cubic centimeter. While one thousand million bacilli appears like 

 an excessively high figure, it is not really so in view of the fact that 

 one cubic centimeter of rat's blood contains 10,000,000,000 red blood 

 corpuscles, and that in some of the other hemorrhagic septicemias, 

 particularly those in birds, the bipolar bacilli are often many times 

 in excess of the number of red blood corpuscles. 



FIG. 126 



Bacterial embolism in a vessel of the kidney (centre of field). Human infection by the bacillus 

 of bubonic plague. (Author's preparation.) 



Plague in Man. According to the author's observations, this is 

 generally not a septicemia but a local infection with a general toxemia. 

 If blood in amounts of several cubic centimeters is obtained from 

 plague patients and properly incubated in fluid culture media a growth 

 is often obtained, but this may be due to the presence of a very few 

 bacilli, and it only proves that a few live bacilli were in the blood at 

 the time it was taken. In a true septicemia, however, a multiplication 

 of the bacteria in the blood must be demonstrable. True hemorrhagic 

 plague septicemia and pyemia with the formation of bacterial emboli 



