CONDITIONS INFLUENCING PREVALENCE 153 



elaborating and systematising our knowledge of their life 

 history within the blood-vessels of the human subject. 



Following on these we have the undoubtedly pioneering 

 observations of Major Eoss, I.M.S., on the life history 

 of the stage of the parasite which is passed within the 

 mosquito, which are all the more remarkable when the 

 conditions under which he worked are understood. Condi- 

 tions under which those accustomed only to the luxurious 

 ease of a European laboratory with dozens of assistants 

 well-nigh as able as themselves to lighten the work, would 

 probably find so untenable that it may be doubted if they 

 would succeed in observing at all. But even under the 

 most favourable conditions, initial observations of the sort 

 must needs be always more or less incomplete and that 

 some inaccuracies should be discoverable in Ross's work is 

 merely equivalent to stating that the work was of an initial 

 and pioneering character. Eoss's observations have been 

 now confirmed and elaborated by the admirable work of 

 Grassi, but there still remain some points to be elucidated 

 before our knowledge of the life history of the parasite 

 within the mosquito can be considered as complete. Finally, 

 it has been clearly demonstrated in Italy that man can be 

 inoculated with malaria by the bite of infected Mosquitoes 

 of the Genus Anopheles and quite recently Major Andrew 

 Buchanan, I.M.S., has recorded in the April issue of the 

 hidian Medical Gazette, a number of carefully conducted 

 experiments which establish the same fact for India. 



The Italian observers, having the advantage of working 

 in a country, highly malarious, and yet provided with fully 

 equipped laboratories, and all the resources of an advanced 

 civilisation have been able to conduct their experiments 

 with an exactness of precaution quite unattainable in the 

 semi-civilised haunts of tropical malaria, and to the un- 

 prejudiced critic, leave no really fair ground for objection ; 

 but they still leave it open for the superficial objector to 

 suggest that, being inhabitants of a notoriously malarious 

 country, the subjects of experiment may have been infected 

 in some other way than through the agency of the experi- 

 mental Mosquito bite. The standpoint of these last 



