265 



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 oiie 

 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. 



3. Make dry blood films by the method des- 

 cribed in the early part of the book. 



4. 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 

 Anopheles 



(The Sporozoit Rate) 



1. Collect as large a number of Anopheltnes 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 extra- 

 ordinarily low, e.g., two per cent., although 

 Anopheltnes are abundant and the malarial index 



