﻿STUDIES IN PLAGUE IMMUNITY. 



Series 31 — Continued. 



227 



a shaved area on the abdomen and the skin lightly scarified with a scalpel. 

 Five control animals were all inoculated in the same manner. 



Animal 

 No. 



Inoculated May 

 14 with— 



Reinoeulated 

 June 11 with — 



Result. 



Autopsy and remarks 



1969 



1970 



1971 



1972 

 1973 

 1974 



5 ce. Artificial 



Aggressin II 



intraperito- 



neally. 



._ . do 



5 oesen suspen- 

 sion of "Pest 

 Virulent." 



do 



Dead June 16, 

 after 5 days. 



Dead June 18, 



after 7 days. 



do .. 



Innumerable pest bacilli in smears 

 from spleen. 



Numerous pest and post-mortem 

 invading bacilli in smears from 

 spleen. 



Numerous pest bacilli in smears 

 from spleen. 

 Do. 



Pest bubo.. Numerous pest bacilli 

 in smears from spleen. 



do _ 



do 



__ do 



do - . 



do 



.... do 



do 



Alive and well . 



Dead June 21, 



alter 9 days. 



do 



. _do .. 







CONTROLS. 



2093 

 2094 



2095 



2096 

 2097 





5 oesen suspen- 

 sion of "Pest 

 Virulent." 



do 



Dead June 16, 

 after 5 days. 



Dead June 18, 

 after 7 days. 



Dead June 16, 

 after 5 days, 

 do 



Pest. 



Numerous pest bacilli in smears 

 from spleen. Hemorrhagic 

 buboes. 



Pest. 



Do. 



Numerous pest bacilli in smears 

 from spleen. 







do .. 





. ..do 





. ..do 



Dead June 18, 

 after 7 days. 







Series 36. — Inoculations with artificial pest aggressin in guinea pigs. 



May 16: Sixty-seven 48-hour large agar slant cultures of "Pest Virulent" 

 (from guinea pig number 1958, second generation) were suspended in 67 cubic 

 centimeters distilled water. The suspension was then placed in a bottle, after- 

 wards sealed and throughly shaken on an electrical "machine for three days. 

 On May 19 cultures were taken, these later showed numerous pest bacilli still 

 alive. A 5 per cent solution of carbolic acid was added to the suspension suf- 

 ficient to form a 0.5 per cent solution and it was then centrifuged for three hours 

 at a velocity of 4,000 revolutions per minute. The centrifugated tubes were then 

 removed and placed for two hours at a temperature between 45° and 46° C. 

 The clear fluid above was then pipetted off and, after its sterility was proved, 

 used on May 20 for the inoculations described in the table below. On July 16, 

 two months later, the animals were all reinoeulated in the following manner: 

 5 oesen of a suspension of "Pest Virulent" (one 48-hour culture from guinea 

 pig number 2174, second transplant) in 5 cubic centimeters of bouillon were 

 rubbed over a shaved area on the abdomen which was scarified with a scalpel. 



