174 THOMPSON YATES LABORATORIES REPORT 
lay in the appreciation of this previously unsuspected and enormous source of 
infection. 
The Liverpool School Expedition found a similar condition of affairs in all 
parts of Nigeria visited by them. 
With a knowledge of the ubiquity of native malaria, the method of infection 
of Europeans becomes abundantly clear. The reputed unhealthiness or healthiness 
of stations is seen at once to be dependent on the proximity or non-proximity of 
native huts. The attack of malaria after a tour up country, the malaria at military 
stations like Prah-su, the abundance of malaria on railways, are all explicable when the 
extraordinary condition of universal native infection is appreciated. 
It is evident that could Europeans avoid the close proximity of native huts 
they would do away with a very obvious and great source of infection. That they 
could avoid the neighbourhood of huts no one who has studied the conditions of life 
in Africa can doubt. On the other hand European houses in tropical Africa are 
almost always to be found with several native huts close at hand. When it is under- 
stood that each of these huts certainly contains many children with parasites in their 
blood, and also scores or hundreds of anopheles to carry the infection, then the 
frequency with which Europeans suffer from malaria is scarcely to be wondered at. 
Sometimes the huts are those of the Europeans' servants, and here a mere 
command would be sufficient to ensure, in a day or two, freedom from such sources 
of infection. In other cases the huts are beyond the control of the European : but 
here again had the site of his house been chosen with a view to health, and situated 
away from huts originally, malaria would have been avoided. Throughout Africa 
Europeans are suffering from constant and repeated attacks of malaria, which owe 
their origin entirely to the presence of these huts, and which might with infinitesimal 
trouble be avoided. 
SUMMARY 
To sum up then the application of these methods to conditions in Africa. 
1 The destruction of larvae is from the magnitude of the task only 
applicable in special conditions. 
2 The methods of protection from mosquito bites are efficient only when 
great personal care is used. These means necessitate the most vigilant and 
unremitting attention, and are therefore more a matter for the individual than a 
community. 
3 (a) The seeking out of cases of malaria, or any drug treatment of the 
natives, is quite impossible in Africa. 
(b) The separation of Europeans from the close neighbourhood of any 
native hut is a way in which Europeans may, without constant 
worry and trouble, protect themselves from malaria. 
