62 



SPECIFICITY OF RICKETTSIA PROWAZEKI 



Histological examination showed the lesions characteristic 

 of typhus in the brains of all three guinea-pigs. From guinea- 

 pig 59, guinea-pigs 78 and 79 were inoculated intraperitioneally 

 each with 2.5 c.c. of blood. 



From guinea-pig 60, guinea-pigs 76 and 77 were inoculated 

 intraperitoneally each with 2.5 c.c. of blood. 



The temperatures of these four guinea-pigs were as follows: 



The autopsy on guinea-pig 79 showed a much enlarged 

 spleen covered with a thin transparent fibrin-like layer. All 

 other tissues were negative. From this guinea-pig the strain 



