﻿270 STRONG. ' 



Series 63 — Continued. 



leucocytes and there were only a few bacteria and a moderate number of leucocytes 

 which contained bacteria in the abdominal cavity. These free organisms, however, 

 took a distinct bipolar stain and some of them appeared eapsulated. Films made 

 by rubbing portions of the omentum upon glass slides and staining the prepara- 

 tions showed numerous polymorphonuclear leucocytes and large mononuclear 

 phagocytes. A number of these contained bacteria, but not nearly so many cells 

 had ingested bacteria as in the case of guinea pigs numbered 2152, 2153. and 

 2157. neither was the number of bacteria in the cells so great. In the abdominal 

 exudate of these animals and in the omentum there was a distinct reduction in 

 the number of the bacteria inoculated and it would appear that the organisms 

 had invaded further into the tissues and to other organs such as the spleen 

 and even the blood. The slight evidence of phagocytosis observed in this animal 

 would appear to be due to the fact that the bacteria had not been acted upon 

 by immune serum. 



Series 64. — Eclating to tlie mechanism of the action of plague immune scrum. 



Guinea pig number 2852 : One agar slant culture of "Pest Virulent" from 

 guinea pig number 2764, second transplant, was suspended in 1 cubic centimeter 

 of saline solution. This suspension together with 1 cubic centimeter of pest 

 immune serum was injected into the abdominal cavity of the animal. Micro- 

 scopic examination of drops of fluid from the abdominal cavity after twenty 

 minutes showed almost complete disappearenee of the bacteria. There were 

 numerous large mononuclear and polymorphonuclear cells present, none containing 

 bacteria. After fifty minutes there was still no evidence of bacteria in the 

 exudate, although the leucocytes were more numerous. The animal was killed one 

 and one-half hours after inoculation. The omentum and posterior abdominal walls 

 showed enormous numbers of bacteria, a large number of which had been ingested 

 by leucocytes. 



Guinea pig number 2853: One agar slant culture of "Pest Virulent" from 

 guinea pig number 2852, second transplant, was suspended in 2 cubic centimeters 

 saline solution. The animal was inoculated intraperitoneally with this suspension. 

 Microscopic examination of drops of fluid examined from the abdominal cavity 

 after twenty minutes showed numerous bacteria, many in groups. Comparatively 

 few leucocytes were present. After fifty minutes apparently not much change 

 had taken place. There were still many bacteria in the exudate and a few cells 

 containing organisms. The animal was killed after one and one-half hours. A 

 few leucocytes were found in the abdominal exudate; a number of these con- 

 tained bacteria. In smears from the omentum enormous numbers of bacteria 

 were found. There was little evidence of phagocytosis. 



Guinea pig number 2593. immune guinea pig: Inoculated intraperitoneally 

 with 1 agar slant culture of "Pest Virulent" from guinea pig number 2764, 

 second generation, suspended in 2 cubic centimeters saline solution. Drops of 

 fluid taken from the abdominal cavity after twenty minutes showed a few cells 

 and a few free bacteria. After fifty minutes, numbers of large mononuclear cells 

 were visible in the exudate, many of these were packed with bacteria, others con- 

 tained bacteria lying about them. These organisms did not stain as deeply as 

 normal bacteria. The animal was killed one and one-half hours after inoculation. 

 An extensive phagocytosis of the bacteria by the cells of the omentum was found to 

 have occurred. But there were also large numbers of bacteria which were not 

 ingested. 



Guinea pig number 2854: One-half agar slant culture "Pest Virulent" (from 

 guinea pig number 2764, second transplant) was suspended in 0.5 cubic centi- 

 meter saline solution. To this suspension was added 0.5 cubic centimeter of pest 



