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in an African village. Instruct him to muster the 

 children of the village. The free display of ' pice,' 

 half-pence, etc., will greatly aid one, and by palpating 

 a few spleens previously to taking blood specimens 

 the children will come readily. It is well first to take 

 the blood of one or two adults or big boys so as to 

 allay fears. In all cases it will be found best to take 

 for granted the willingness of the child, and if the 

 operation is quickly and quietly performed there is 

 little objection, especially when each receives payment. 



Make twenty to thirty dried films or more. 



At the same time a spleen census may with 

 advantage be made. 



On examining the films determine : 



(i) Number shewing parasites or pigmented 

 leucocytes in the blood. 



(ii) The species of each parasite present and 

 the percentage value for each if the numbers are 

 large enough. 



To DETERMINE THE INFECTION IN THE ANOPHELINES 

 (THE SPOROZOIT RATE) 



1. Collect as large a number of Anophelines as 

 convenient from the village in and around which 

 the previous observations have been made. 



2. Dissect as many specimens as possible, noting 

 in each case the species dissected, and noting in which 

 species, if any, sporozoits are found. 



In many cases the sporozoit rate is extraordinarily 

 low, e.g., two per cent., although Anofhelines are 

 abundant and the malarial index is not low. In others, 

 especially in African bush stations, the percentage 

 may reach fifty per cent. 



3. Leave specimens not dissected, for several 

 days, and examine the mid-gut for zygotes. 



