238 
Anopheles in Flanders 
near Abeele and-Hamhoek. Altogether about 12 square miles were inspected. 
Approximately 200 waters were examined, most of them farm pools, though 
streams, canals and shell-holes have also come under survey, and, in number 
and character, it is considered that this sample is representative of the district. 
Twenty-nine Anopheline waters were found, in 20 cases harbouring few larvae 
and in 8 harbouring many. One record is incomplete. That is, 14*5 per cent, 
of the waters examined contained Anophelines or about 1 pool in every 7, 
an average, also, of about 2-4 per square mile. 
Hazebrouck District. This district is small, approximately 3-4 square miles, 
and is composed of open farm land. It contains the town of Hazebrouck and 
the village of Hondeghem. It was searched almost exhaustively and the 
results of the enquiry may be regarded as giving a correct idea of its condition 
in regard to Anopheline distribution. The number of waters was 114, practi¬ 
cally all pools, of which 16 contained Anophelines, 9 with few, 4 with many 
and 3 with a number undetermined. The proportion of infested waters there¬ 
fore was 14 %, or approximately 1 pool in every 7, an average of about 
5 per square mile. 
The results of the more general survey of the region north of the Haze¬ 
brouck district showed 7 infested pools out of the 53 investigated, that is, 
13*2 % or about 1 in every 7 to 8 pools examined. 
Southern District. This district, which is similar in character to the 
Hazebrouck district, was worked in detail for pools in the summer of 1916. 
It is irregular, about 20 square miles in area, the chief villages being Borre, 
Caestre, Pradelles, Strazeele, Fletre, Merris, Meteren and Neuve Eglise, with 
Bailleul as the important town. The only exact records preserved relative 
to this district are those concerning the location of the Anopheline centres 
and consequently the proportion of infested waters cannot be given. A general 
note exists which states that approximately 20 % were Anopheline but in 
view of the recent findings for the Hazebrouck district the statement cannot 
be accepted as final. As, however, the number of infested waters discovered 
was 64 it can be stated that there were 3 Anopheline waters per square mile. 
Rubrouck District. This district, about 3 square miles in area, consists of 
open level farm country and the villages around which the survey extended 
were Rubrouck and Broxeele. The survey was a fairly detailed one but, 
being made by assistants, it is probable that certain infested waters were 
overlooked owing to the lack of training of these workers. Out of approxi¬ 
mately 183 waters examined, 10 were found to be Anopheline, that is, 5*5 %, 
or 1 pool in 18, an average of 3 per square mile. The number of larvae was 
not noted by the observers. 
Central District. This district of about 5 square miles includes the high- 
lying villages of Godewaersvelde, Boeschepe and Berthen and the land sloping 
away from them. The altitude rises abruptly to 200 feet above the sea level. 
