TRANSMISSION OF THE INFECTION. 147 



The cultures formerly made from the colonies on the plate resulted as 

 follows; 25 A l=:a coarse bacillus with sciuare ends; decolorizes by Gram's 

 stain; this culture was later inoculated into j^uinea pip No. 5307 by the 

 cutaneous method; the animal remained healthy. Culture 25 A 2 = a bacillus 

 which decolorizes by Gram; ji^rowth on ajjar appears somewhat heavy for the 

 play:ue bacillus; inoculated later into jjuinea pij^ No. 5459; this animal 

 died of typical plague infection after five days. 25 A 3, 8, and 9=:cultures 

 of a spore-bearinjr bacillus; heavy white prowth on afjar. 25A4 = a 

 bacillus which partially decolorizes by Gram, but whose morphology is 

 not rijrht for plague and whose jj:rowth on a^ar is much heavier than that 

 of the plague bacillus. 25 A 5 and 6 = heavy white colonies; the same 

 bacillus as 25 A 4. 25 A 7 decolorizes by Gram; morpholojjcy looks rijjht; 

 this culture was later inoculated into puinea pig No. 5460 which died six 

 days later of typical plapue infection. 



Plate B. Patient talked a little during the time of the e.xpo.sure and 

 coughed once. Result after forty-eight hours: Sixteen colonies and a large 

 surface growth. Only 3 of the colonies could possibly be colonies of the 

 plague bacillus. These were planted on agar slants as follows: 25 B 1, 

 colonies too heavy for plague; = a large spore-bearing bacillus. 25 B 2, a 

 large bacillus; morphology not right, ends square, partially decolorizes; 

 growth on agar not right for plague. 25B3 = a bacillus which partially 

 decolorizes; 1 esse of this culture was later inoculated into guinea pig 

 No. 5308 by the cutaneous method; this animal remained healthy. 



Plate C. No cough while exposed. Patient talked most of the time. 

 Result after twenty-four hours: Eleven colonies. Result after forty-eight 

 hours: Sixteen colonies. Only 4 of these colonies could possibly be those 

 of the plague bacillus. These were planted on agar slants as follows: 

 Culture 25 C 1, the colonies might be those of the plague bacillus, but are 

 a little heavy. The organism is a bacillus which decolorizes by Gram; 

 0.5 cese inoculated subcutaneously into mice Nos. 18 and 26; both of these 

 animals remained healthy; 1 cese of this same culture was later inoculated 

 into guinea pig No. 5467 by the cutaneous method; the animal remained 

 healthy. 25 C 2 and 3, the colonies have a yellowish-gray tinge; evidently 

 not plague. 25 C 4, colonies have a deep yellowish-orange color; evidently 

 could not be plague. 



SERIES VIII. 



Case 28. — With much bloody sputum, containing large numbers of 

 plague bacilli. Temperature 38 °C., pulse 132. Patient died twelve hours 

 after exposure of plates. Physical signs in the lungs very slight. 



Plate A exposed for two minutes at a distance of from 11 to 15 cen- 

 timeters. Patient snored during the time of exposure. Result after forty- 

 eight hours: The whole plate covered with a very heavy buff -colored 

 surface growth. Plate, therefore, discarded. 



Plate B exposed for two minutes at a distance of from 11 to 15 cen- 

 timeters. Patient coughed slightly once during the time of exposure. 

 Result after forty-eight hours: Sterile; no colonies have developed. 



Plate C exposed for two minutes at a distance of from 11 to 15 cen- 

 timeters. Patient coughed severely once. Result after forty-eight hours: 

 About two hundred small colonies scattered over all parts of the plate, 

 from pin-point to pin-hoad in size; one large light, bufF-colored colony 

 with irregular marg^ins. A number of the small colonies planted upon 



