TRANSMISSION OF THE INFECTION. 149 



shows a very larj^e bacillus which does not decolorize. Cultures 28 F 3 and 

 5 reveal a coarse bacillus which only partially decolorizes; these cultures 

 were later inoculated into guinea pi^s Nos. 54G8 and 54G9 by the cutaneous 

 method; both of these animals remained healthy. 



Plate G exposed at a distance of about 70 centimeters. Patient requested 

 to coufrh, which he did 8 times. Plate exposed for a few seconds during 

 the period of couj^rhinfr. Result after forty-eight hours: About 100 colonies 

 are scattered over the surface of the plate from pin-point to pin-head in 

 size and up to a little larger in diameter. Thirteen of these colonies which 

 resembled more or less colonies of the plague bacillus were planted on 

 agar slants. One-fourth cese of several suspicious-looking colonies on the 

 plate were inoculated subcutaneously into mouse No. 14, and another 0.25 

 oese of these colonies into mouse No. 15; one animal died forty-eight hours 

 later and the other five days later of plague infection; in the first, the 

 inguinal glands were swollen and contained innumerable plague bacilli, 

 while in the second there was a typical left inguinal bubo; innumerable 

 plagxie bacilli were present in the spleen of each animal. All the colonies 

 on the plate (28 G) exposed before this patient were suspended in a few 

 drops of saline solution and several cesen rubbed over the shaved and 

 scarified abdomen of guinea pig No. 19; the animal died three days later 

 with typical buboes and plague spleen; smears from the bubo and spleen 

 showed innumerable bipolar organisms. The results of the agar-slant- 

 cultures made previously from the colonies on the plate are as follows: 

 Culture 28Gl = a bacillus which does not decolorize. 28G2=:a bipolar 

 staining bacillus which decolorizes. Inoculated later into guinea pig No. 

 5455 by the cutaneous method; the animal died six days later of typical 

 plague infection. 28 G 3 did not develop on agar. 28 G 433 a bipolar 

 organism which decolorizes by Gram's stain. 28 G 5, a similar organism 

 to 28 G 4 ; inoculated later into guinea pig No. 5456 by the cutaneous 

 method; the animal died six days later of typical plague infection. 

 28 G 6 = a bacillus which does not decolorize by Gram's stain 28 G 7, 8, and 

 9 = a bipolar organism which decolorizes by Gram's stain; 28 G 9 inoculated 

 later by the cutaneous method into guinea pig No. 5324, which died of 

 typical plague infection five days after inoculation. 28 G 10, a very short 

 bacillus which does not decolorize. 28 G 11, 12, and 13, a bipolar organism 

 which decolorizes by Gram's stain; probably the plague bacillus. 



28 H, ward plate, exposed in the center of the ward at about 2 meters 

 from the nearest coughing patient. Time of exposure, four minutes. 

 After forty-eight hours, only 2 isolated, large white colonies and a surface 

 growth over about one-half of the plate had occurred. Plate discarded. 



Plate 28 I, ward plate, exposed in the same manner, 2 meters from 

 coughing patient, as Plate H for ten minutes. Light surface growth covers 

 the entire plate. There are a few colonies situated beneath this. Plate 

 discarded. 



SERIES IX. 



Case 29. — Three plates exposed for a few seconds each about a quarter 

 of an hour before death of the patient, at a distance of about 11 centimeters 

 from the mouth. Much vapor arising from the breath. No cough during 

 time of exposure. Result after forty-eight hours: On all 3 plates, no 

 colonies have developed; after seventy-two hours, plates still sterile. 



