142 STRONG AND TEAGUE. 



as though they might be those of the plague bacillus, but microscopically a 

 number of them consist of a large bacillus which does not decolorize by 

 Gram's stain. 



Case 2. — Plate exposed for two minutes at a distance of 11 centimeters. 

 No coughing. Result after forty-eight hours: One large colony of a coarse 

 bacillus which does not decolorize. A group of several hundred pin-point- 

 sized colonies; evidently not plague colonies. Microscopical examination 

 shows a large bacillus in long chains. 



Case 3. — Plate exposed at a distance of 90 centimeters from the mouth 

 for fifteen minutes. No coughing. Result after forty-eight hours: About 

 20 scattered colonies and a patch of several thousand (?) colonies that 

 do not look at all like colonies of the plague bacillus. A number of these 

 colonies examined consist of a fine bacillus which does not decolorize by 

 Gram's stain. 



Case U- — Plate exposed for one minute at a distance of 11 centimeters. 

 No coughing. Result after forty-eight hours: Negative. 



SERIES IV. 



Case 1. — Advanced case with bloody sputum. Much vapor arising from 

 the mouth. 



Plate A exposed for two minutes at a distance of 11 centimeters. No 

 coughing. Result after forty-eight hours: One large spreading colony, 

 evidently not plague. Two large white colonies, evidently not plague. 

 Two pin-head-sized colonies might possibly be plague colonies. On March 

 17, only 3 colonies are present on the plate that could possibly be plague. 

 These were transplanted and studied. They all consist of a very short 

 bacillus which partially decolorizes by Gram's stain. This organism was 

 later inoculated by the cutaneous method into guinea pigs Nos. 5462 and 

 5477, which remained healthy. 



Plate B exposed in similar manner to Plate A. No coughing. Result 

 after forty-eight hours: One-half of the plate is overgrown by a surface 

 growth; the other portion is free from colonies. Discarded. 



Case 2. — With much bloody sputum. Vapor arising from the mouth 

 during respiration. 



Plate A exposed for two minutes at a distance of 11 centimeters. 

 Patient coughed four times during exposure. Result after twenty-four 

 hours: Almost the whole surface of the plate covered with a thick growth, 

 which may be that of the Hay bacillus. In addition, there are 14 pin-head- 

 sized colonies which may be seen beneath this growth. Plate discarded. 



Plate B exposed for two minutes at a distance of 11 centimeters. 

 Patient coughed three times during exposure. No visible sputum on plate. 

 Result after forty-eight hours: Entire plate overgrown, except near the 

 edge. Here are situated 5 small white colonies. Two of these are pin- 

 point in size; the others are larger. The large colonies = a bacillus 

 which does not entirely decolorize. The small colonies entirely decolorize 

 by Gram's stain. One of these planted on an agar slant and later in- 

 oculated cutaneously into guinea pig No. 5486, which died of typical 

 plague infection with early inguinal buboes, four days after inoculation. 

 The whole plate-culture was suspended in a little saline solution, and 

 several oesen of this suspension rubbed over the shaved and scarified 

 abdomen of guinea pig No. 11. This animal died four days later. At 

 necropsy there were typical inguinal buboes and a typical plague spleen. 



