PART 1.1 Direct Contagion Questioned in the Non-Endemic Area. 293 



the last few years. This has been done designedly, in order to avoid complications, 

 incident on the discussion of two different questions simultaneously. The present 

 report deals with phenomena, which are common both to the period previous to, and 

 to that following, the diminution. To have attempted to combine the discussion of 

 the cause of the diminution in absolute prevalence with one regarding the cause of 

 the variations in relative prevalence characterising different periods of the year, could 

 only have led to confusion and obscurity. 



(b) As observed in the localities in the Endemic area other than Calcutta. 



The foregoing remarks apply with equal force to the relation which various 

 physical conditions bear to the prevalence of cholera in the other districts in the 

 Bengal Presidency in which the disease may be said to be endemic. It will have 

 been observed that in the stations which have been selected to represent the principal 

 districts in the endemic area taken as a group, the seasonal manifestation of the 

 disease presents a striking resemblance to that in Calcutta — 82 per cent, of the total 

 annual cholera taking place during the eight drier months of the year in Calcutta, 

 and 71'2 in the stations taken as a group, the maximum cholera in both occurring 

 during the comparatively dry months of March and April, \yide Table UV.] 



As, however, the figures available regarding the prevalence of the disease at the 

 individual stations of this group are so small compared with the statistics in Calcutta, 

 which embrace the general population, it is not to be expected that the monthly 

 proportions should accurately agree. Nothwithstanding this, however, and the difference 

 in the surroundings of the classes of the population compared, even the monthly 

 statistics, especially when weeded of manifestly casual occurrences, present a marked 

 general similarity. It is therefore obvious that the conclusions derived from the data 

 regarding Calcutta apply generally to this group of stations also. 



(c) As observed in the Non-Endemic Area. 



Seeing, however, that in those parts of the Bengal Presidency in which cholera 

 manifests itself at irregular intervals only, it displays a preference for other than the 

 dry months of the year, it will be necessary to consider whether the foregoing remarks 

 concerning the more prominent doctrines regarding the causation of the disease still 

 retain their applicability. 



(1) With regard to the theory of direct contagion, it was observed that the fact 

 that cholera-prevalence in the endemic area was at a minimum when, for climatic 

 reasons, the people (during the rainy and cold seasons) were most crowded together, 

 tended to negative the view that personal contact exercised any important element 

 in the extension of the disease. 



In the Upper Provinces, notwithstanding the still closer relation which must 

 exist between individuals owing to the greater severity of the cold, cholera falls to its 



