A. D. Peacock 
239 
The waters examined lay in the vicinity of the roads intersecting the district 
and numbered 12, and were mostly pools. The comparatively small number 
is due to the fact that the waters appeared to be less numerous than in the 
surrounding lower-lying country. No Anopheline waters were discovered but 
in view of the small number of sites examined it cannot be asserted that no 
Anophelines existed. 
Waterlands District. The waterlands of this part of Flanders are wide¬ 
spread and low-lying and are characterised by the presence of many canals 
which intersect them and the network of ditches of varying widths and 
depths. In the Second Army area the wacerland region is irregular and not 
of great extent, being about 15-20 square miles. It penetrates the north-west 
boundaries of the army zone and is almost detached from the main water- 
lands to the north, the junction between them being narrow and running 
between high land on either side. The regions surveyed were part of the 
south-west fringe of the main waterlands, from Millam and Watten, about 
\\ miles and the area bounded by imaginary lines joining Watten, Moulle, 
St Omer and St Momelin. The latter region is about 10 square miles in extent 
and is bounded on the east by the canal between Watten and St Omer, 
which receives all the drainage from the western network cf streams and 
i 
ditches. Particular attention was directed to pools in the vicinity of Moulle 
on the west, pools and ditches near Bleue Maison and Watten in the north, 
pools near St Momelin on the east and the main canal and a ditch running 
roughly north and south between Watten and St Omer. To the north, waters 
round the villages of Wylder and Rexpoede were investigated by Lance- 
Corporal Newman, R.A.M.C. 
Near the village of Millam 4 Anopheline pools were discovered, 2 con¬ 
taining numerous larvae and 2 with few. The long ditch running by the side 
of the road from Millam to Watten was typical of the district. In width it 
varied from 4 to 8 feet and in depth to about 4. It received the drainage 
from smaller ditches on the eastern slopes. It was very rich in flora and the 
greater proportion of it was covered with water vegetation, open patches of 
water being exceptional. The predominant water weeds were marestail 
(Hippuris), starwort (Callitriche), duckweed ( Lemna) and fringed water-lily 
(Limnanthemum) while water-cress ( Nasturtium ) and algae ( Spirogyra mostly) 
were also present in places but, compared with the other plants, were small 
in quantity. Marginal rushes were also found but the banks were mostly 
grassy. The larger fauna consisted of eels (Anguilla), sticklebacks (Gastero- 
steus), fresh-water shrimps (Gammarus) and water hog-lice ( Asellus ). Ex¬ 
aminations were made in at least 7 places along this ditch, many dippings 
being made at each examination but Anophelines were found in only two 
places and in small numbers. The first capture of 3 small larvae was made 
by repeatedly skimming the water above the algae and fringed water-lily, 
the second capture, 5 small larvae, by the same method above algae. 
Parasitology xn 
16 
