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gon to the Mexican border. Once planted in this ideal soil, infec- 

 tion may never be uprooted or its growth and extension controlled. 

 Small outbreaks will occur here and there, and periodical visitations 

 of greater magnitude may be expected in cities where a combination 

 of epidemiological factors is permitted. 



The facts as set forth in this paper have caused grave apprehension 

 in the minds of those who have been at all conversant with the con- 

 ditions in the transbay counties since 1903. At that time the writer 

 recognized the probability of the establishment of a permanent focus 

 of plague in that locality, and subsequent discoveries have proven 

 the correctness of the assumption. This changes the aspect of the 

 problem from that of a local infection to one of national importance. 

 Once established in such a rural community, plague is dislodged with 

 difficulty and only after a campaign covering a considerable length of 

 time. Being a national problem it can be best solved by the Federal 

 Government. 



REFERENCES. 



The Croonian Lectures on Plague, W. J. Simpson; Journal of 

 Hygiene, Volume VI, No. 4; Volume VII, No. 6; Volume VIII, No. 2; 

 Plague among the Ground Squirrels of California, W. B. Wherry, 

 Journal Infectious Diseases^ Volume V, No. 5 ; California Mammals, 

 Frank Stephens. 



