128 Dr Stephens, The Prevention of Malaria. 



Table III. 













Ti 



a 







to 



a 



H3 03 



0) cd 



CO 



CD 



"5 a 



rS' 73 



House 





o 



CM 



a 



cd o 



9 o 

 so es 



CD 

 O 

 CO 

 CD 

 M 

 O 



o 



■81 



03 H 



-)-3 CD 

 O 



H 



1 







1 



2 



2 



4 



2 



No children 













3 









1 



1 



1 



4 





1 



2 



3 



4 



5 



5 







1 





1 



1 



6 









2 



2 



3 



7 



One child only 











1 



8 







1 





1 



1 



9 



No children 













10 



No children 















Total 





8 



11 



1-6 



6 



We have briefly described the distribution of Anopheles in some 

 typical malarial parts of W. Africa and also the conditions which 

 determine the existence of breeding grounds. A conception of 

 these conditions is necessary before undertaking any measures for 

 the destruction of Anopheles or their breeding grounds; but an 

 actual knowledge of the places can only afford a really adequate 

 idea of the conditions, and it is a want of complete knowledge on 

 these points that has led to many immature schemes for wholesale 

 destruction of mosquitoes and to an unrealised predicted freedom 

 from malaria. But as we have already pointed out it is not 

 so much the question of distribution of Anopheles that is important 

 as the absolutely fundamental question, what is the source of the 

 infection of Anopheles and how can Europeans protect themselves 

 from infection ? 



Before this work on native children was done, it had been 

 thought that the source of infection was the European conva- 

 lescent from an attack of fever ; for it is in this state that gametes 

 usually occur (we shall point out later however that as a matter of 

 fact in W. Africa they rarely do occur). But it was always 

 difficult to understand how the same mosquitoes which had got 

 infected from such (supposed infective) cases should again find out 



