37G APPLICATION OF METHODS OF BACTERIOLOGY 



suggested that possibly the organisms found by Kitasato 

 in the blood, and which he describes as pest bacilli, that 

 retained the color when treated by the method of Gram, 

 were pairs of micrococci, and not bacilli at all. 



It is the opinion of Aoyama that the suppuration of the 

 glands is not caused by the plague bacillus, but is rather the 

 result of the action of the pyogenic cocci with which it is 

 so often associated. It is also his belief that the most impor- 

 tant and frequent mode of infection in man is through 

 wounds of the skin. He does not regard either the air- 

 passages or the alimentary tract as frequent portals of infec- 

 tion. Wilm, on the contrary, is inclined to regard the 

 alimentary tract as a frequent portal of infection;' and there 

 is a general concensus of opinion that in the pulmonic 

 type of plague, its most fatal manifestation, infection is 

 always by way of the respiratory tract. 



The order in which the lymphatics manifest disease ap- 

 pears to depend upon the location of the primary infection. 

 That is to say, if it is upon the feet, as of persons who go 

 barefooted, the superficial and deep inguinal glands are the 

 first to show signs of the disease; while if infection occurs 

 through wounds of the hand, the buboes appear first in the 

 axillary region. As a rule, the wound through which infec- 

 tion is received shows little or no inflammatory reaction.^ 



Wyssokowitz and Zabolotny^ call attention to the fact 

 that the blood of patients convalescing from plague has an 

 agglutinating action upon fluid cultures of the plague bacillus 

 analogous to that observed when the blood-serum of typhoid 



> Wilm, Hyg. Rundschau, 1897, p. 217. 



2 The works of Yersin, of Kitasato, and of Aoyama have been exhaust- 

 ively reviewed by Flexner in the Bulletin of the Johns Hopkins Hospital, 

 1894, V, 96, and 1896, vii, 180. I am indebted to these reviews for much 

 that is here presented on this subject. 



' Annales de I'lnstitut Pasteur, 1897, p. 663. 



