modification of the Romano vsky, colors the bacterial cell "7Q 

 nucleus blue, while the capsular substance found on agar 

 cultures of B-pestis and B-bovisepticus takes the eosin. I 

 have had some photomicrographs taken showing the stained 

 capsules which you will like to see. 



The story of this rat made an article [12] entitled The 

 bacteriological examination of a plague rat the following 

 November. Here he said that he was out of patience with 

 the "rough and ready" methods generally employed for the 

 diagnosis of the disease and wished to prove scientifically 

 that Manila plague was really plague. "One grows tired of 

 reading of the occurrence of plague in pigs, dogs, jackals, 

 snakes, etc, without the presentation of sufficient evidence." 

 Whereafter his account brought the proof in anatomical and 

 bacteriological form — in excellent example to less experienced 

 workers of how to do such things. But Wherry got quickly 

 from this to a discussion of more abstract notions of infection. 

 He had found a new method for staining the capsules about 

 bacteria, and noted that his pest organism showed none as 

 taken from the body, but developed them soon after it had 

 been made to grow on artificial media. This raised anew a 

 question of Theobald Smith: Is capsule production a method 

 of defense against an unfriendly surrounding? Smith had 

 written: "The formation of protective or defensive cover- 

 ings . . . would account for certain phenomena, which are 

 familiar to bacteriologists, much better than the current 

 theory which bases parasitism exclusively upon toxine pro- 

 duction, active or passive. In cultures we should expect a loss 

 of power to form protective substances . . . " In the specific 

 instance of plague, Wherry's findings said the contrary. 

 Whereafter he gave evidence of the broad fashion in which 

 he always looked upon disease from a natural history point 

 of view. The capsule formation had to do with the universal 

 battle in all infection between host and attacker. And now 

 he asked about the rats which harbored the fleas that trans- 

 mitted the plague. He wanted to know what kinds of rats 

 were chiefly to blame. On this subject he reported some three 

 years later. At the moment he displayed for view a dramatic 

 biological set-up. "Bruce Skinner has presented evidence 



