﻿STUDIES IN PLAGUE IMMUNITY. 



219 



Series 38.- — Inoculation with the strain "Maassen AW in guinea pigs. 



May 20: Eight 24-agar slant cultures of "Maassen Alt" were suspended in 8 

 cubic centimeters of normal saline solution (1 cubic centimeter to each culture) 

 and each animal was inoculated intraperitoneally with 1 cubic centimeter of the 

 suspension. One animal succumbed from the effect of the vaccination. On July 

 16, about two months after the vaccination, the animals were all reinoculated, 

 5 oesen of the same suspension of "Pest Virulent" employed in reinoculating 

 Series 32, 33 and 37 being rubbed over a shaved and scarified area on the abdomen. 

 The same twenty-five control animals, numbered 2098 to 2122, employed in Series 

 32 and 33 (see pp. 204 and 218), which all died, answered for controls for 

 the present series. 



Animal 

 No. 



Vaccinated 

 May 20, intra- 

 peritoneally 

 with— 



Infected 

 July 10 with— 



Result. 



Autopsy and remarks. 



2045 



One 24-hour 

 culture 

 "Maassen 

 Alt." 



5 oesen suspension 

 of "Pest Virulent" 

 rubbed over abdo- 

 men. 



Alive and well . 





2046 



_.__do ... 



....do __ _ 



Dead July 31, 



Very few pest bacilli in smears 









after 15 days. 



from the spleen. Small 

 bubo. 



2047 



do 



do 



Alive and well 





2048 

 2049 

 2050 



_ do_ 



do . .. 



_ do.. 



Culture from heart and spleen 



_ . do 



__ .do __ 



do 



. do 





Dead Mav 22, 2 









days after 



negative. From the abdo- 









vaccination. 



men about 100 colonies of 

 "Maassen Alt." 



2051 



do... ... 



5 oesen suspension 



Dead July 21, 



Fair number of pest bacilli and 







of "Pest Virulent" 



after 5 days. 



numerous post-mortem 







rubbed over abdo- 





invading bacilli in smears 







men. 





from spleen. 



Series 40. — Inoculations with the strain "Maassen Alt" in guinea pigs. 



June 15: Fifteen 24-agar slant cultures of "Maassen Alt" were suspended in 

 15 cubic centimeters saline solution, and each guinea pig inoculated subcutane- 

 ously with 1 cubic centimeter of this suspension. On August 3, nearly one and 

 one-half months after the vaccination, the animals were all but one reinoculated, 5 

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

 number 2204, second transplant, in 5 cubic centimeters bouillon) being rubbed over 

 a shaved area on the abdomen which was lightly scarified with a knife. It is to 

 be noticed that these animals were all inoculated in exactly the same manner 

 as those described in Series 39. The same twenty control animals, numbered 

 2249 to 2268 (see p. 209), which all died, also served for the present series. 

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