﻿228 



STRONG. 



Series 36 — Continued. 



It will be seen that these animals were inoculated in exactly the same manner 

 as those used in the experiments described in Series 32 and 33. ( See pp. 204. 

 and 218.) The same twenty-five control guinea pigs, numbered 2098 to 2122, 

 inoculated in the same manner, served for the present series as well. All of them 

 died of acute pest infection. 



Animal 

 No. 



Immunized 

 May 20. with— 



Infected July 16, 

 with— 



Result. 



Autopsy and remarks. 



2018 



5 cc. Artificial 



5 oesen suspen- 



Dead July 22, 



Moderate number of pest bacilli in 





Aggressin III. 



sion ''Pest 

 Virulent" 

 massaged 



over abdo- 

 men. 



after 6 days. 



smears from spleen. 



2019 



. do 



do 



Dead July 23, 



Innumerable pest bacilli in smears 









after 7 days. 



from spleen. 



2020 



do . 



do ___ ___ 



.do 



Typical pest spleen. 

 Few pest bacilli in smears from 

 spleen. 



2021 



do 



. do... 



Dead July 21. 

 after 5 days. 









2022 



do 



do 



Dead July 23, 



Typical pest spleen. . 









after 7 days. 



2023 



do 



do____ . 



Dead July 25, 



Advanced bubo. Innumerable pest 

 bacilli in smears from spleen. 









after 9 days. 



2024 



do_ - 



_do_. . 



Dead July 23, 



Numerous pest bacilli in smears 

 from spleen. 









after 7 days. 



2025 



... do 



do 



do 



Few pest bacilli in smears from 











spleen. 



2026 



. do 



.do- 



Dead July 25, 

 after 9 days. 



Typical pest spleen. 









2027 





do 



Dead July 23, 



Innumerable pest bacilli in smears 

 from spleen. 





" Aggressin III. 





after 7 days- 



2028 



2 cc. Artificial 

 Aggressin III. 



.. _do 



Dead July 25, 



after 8 days. 



Numerous pest bacilli in smears 

 from spleen. 





2029 



2i cc. Artificial 

 Aggressin III. 



__do 



Dead July 23, 

 after 7 days. 



Do. 





Series 42. — Inoculations with artificial pest aggressin in guinea pigs. 



On July 16, sixty 48-hour agar cultures of the strain "Pest Virulent" (from 

 guinea pigs numbered 2174 and 2175, second transplant) were suspended in 60 

 cubic centimeters distilled water, 1 cubic centimeter to each culture. The suspen- 

 sion was then placed on an electrical shaking machine for five days. The prepara- 

 tion of the artificial aggressin from this point on was then continued in exactly 

 the same manner as described in Series 29 (p. 223). After it was centrifuged, 

 cultures from the clear fluid showed the aggressin to be sterile. 



On July 23 each guinea pig was inoculated subcutaneously with 5 cubic centi- 

 meters and again on August 1, each animal receiving a repetition of this dose. 

 On August 24, about three weeks after the second inoculation the immunity 

 of the animals was tested by massaging the abdomen with a portion of the 

 spleens of guinea pigs numbered 2315 and 2316, just dead of acute plague infection. 

 Two control animals were inoculated at the same time and in the same manner. 



