218 IMFOETANT VABIBTIES OF FISSION-FUNGI. 



Pathogenic Properties for Man. — Cause of the true 

 oriental bubonic or glandular pest ; also of the pest pneu- 

 m onia. Mortality 50 % -80 % . The gates of entrance are : 

 (1) Skin. The bacteria usually first become localized 

 and grow in the nearest lymph-glands (gland-pest), but 

 often there develops at the place where the bacterium 

 enters a pest pustule, which may be of the character of 

 a boil or carbuncle, and may contain ver}' many bacteria. 

 Death may occur without the pest bacteria extending 

 beyond the local area, but usually it follows a dissemina- 

 tion of the bacteria throughout the entire body (pest 

 sepsis). Rarely pest bacteria also, occur in great numbers 

 in the internal organs ; at times in the urine. (2) Lungs ; 

 pest pneumonia. In the sputum there are very numerous 

 pest bacteria, often also in the blood. Complication with 

 streptococci is frecjuent. (3) Digestive canal ; uncertain. 

 In animals it has been demonstrated. 



Experimental Investigations Regarding Patho- 

 genic Effects. — Almost all animals are susceptible to pest. 

 Pigeons are immune ; dogs and cows but slightly suscepti- 

 ble (Gosio, H. R., 1897, 855); more susceptible are swine, 

 horses, cats ; yet more, monkeys and rabbits ; and most 

 of all, guinea-pigs, mice, and rats. Compare Nuttall (C. 

 B. XXII, 87). The pest bacillus may also become ac- 

 climated to frogs (Devell, C. B. xxii, p. 382). 



Guinea-jDigs inoculated intraperitoneally die in two days 

 of an acute septicemia with few bacteria in the tissues. 

 After infection with small quantities of pest bacilli, death 

 occurs on the sixth day, when the mesenteric glands are 

 swollen and there are hemorrhages in the liver and lungs, 

 together with submihary abscesses and nodular thickenings 

 of the omentum. The spleen contains whole swarms of 

 bacteria, which are united in a zooglear mass. These 

 zoogleffi are formed by very much s^^'ollen capsules. Honl 

 (C. B. XXII, 100). 



Guinea-pigs are easily infected through the digestive 

 tract, in which case there is a special tendency to chronic 

 forms. (Nodules in various organs, including lungs.) 

 Bandi and Stagnitta-Balistreri (Z. H. xxviii, 261). 



Flies transport pest bacilli ; bugs and fleas remove pest 



