INFECTION AND METHOD OF DEVELOPMENT. 177 



Monkey No. 5883 was found dead on November 15, eight days after 

 infection. Necropsy: The tonsils are pale; they contain few pest bacilli 

 and many cocci. The submaxillary, deep cervical, and axillary glands are 

 small and deep red in color. A gland at the bifurcation of the bronchi 

 is enlarged and reddish black in color and contains many plague bacilli. 

 The pharynx and larynx are slightly reddened. The trachea contains some 

 pale, frothy fluid. The lungs are pale and show no pneumonic areas. 

 Cultures made. The spleen is enlarged, deep red, firm, and contains large 

 numbers of plague bacilli. The blood also contains large numbers of plague 

 bacilli. 



Guinea pig No. 5902 inoculated with the spleen of monkey No. 5883. 

 Died in four days with large numbers of plague bacilli in its spleen and 

 with well-marked buboes. 



Guinea pig No. 5901 inoculated with the lung of monkey numbered 

 5883. Died in seven days with large numbers of plague bacilli in its spleen 

 and with well-developed buboes. 



Monkey No. 5884 was found dead on November 14, seven days after infec- 

 tion. Necropsy: (By Dr. Crowell.) The tonsils and pharynx are consider- 

 ably reddened and covered with frothy fluid. The tonsils are small and pale, 

 show no haemorrhages, and are probably not enlarged. The submaxillary 

 glands are slightly enlarged and deep red. The deep cervical glands are 

 somewhat enlarged and deep red, redder than the submaxillary. The glands 

 in both axillae are enlarged and haemorrhagic, those in the left being larger 

 than in the right. A gland at the bifurcation of the trachea is small, but 

 deep red in color. The larynx and trachea are slightly reddened throughout 

 their extent and contain abundant frothy, slightly blood-tinged fluid. The 

 lungs show on the surface only a few small red areas. No pneumonia is 

 present. On section, the cut surface is dark red and very moist. The 

 spleen is enlarged and fairly firm. 



EXPERIMENT II. 



Culture No. 32 isolated from a pneumonic-plague case at Mukden 

 was passed through a series of guinea pigs and a fresh culture from 

 one of these passage guinea pigs was suspended in saline solution. 

 A glass rod was dipped into this suspension and touched against the 

 pharynx of three monkeys (Nos. 5927, 5928, 5929) as in the preceding 

 experiment. The following necropsy reports show that the bacilli from 

 artificial cultures brought about the same result as those inoculated directly 

 from the pneumonic lung. 



Monkey No. 5927. — Bacillus pestis placed on mucosa of mouth December 

 5. Found dead six days later. Necropsy: (By Dr. Crowell.) The axillary 

 glands in the right axilla are slightly reddened, in the left they are pale. 

 The tonsils show no visible change. There is no pneumonia present. The 

 spleen is somewhat enlarged. Smears from the heart show numerous 

 bipolar organisms. The spleen contains involution forms. The liver con- 

 tains numerous bipolar organisms which are less numerous, in the lungs 

 than in the blood. 



Monkey No. 5928. — Bacillus pestis placed on mucosa of mouth December 

 5. The animal died December 14. Necropsy: (By Dr. Crowell.) The 

 tonsils, deep cervical, submaxillary, and axillary glands are only slightly 

 swollen and reddened. The lungs are somewhat oedematous and a little 



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