A. D. Peacock 
243 
Analysis of the types of 173 Anopheline waters discovered. 
Pools, etc. 
127 (73-4 %) 
Pools, 121; lakes, 2; moats, 4. 
Holes 
16 (9-25%) 
Shell-holes, 8; pits, 8. 
Streams, etc. 
12 (6-9%) 
Streams, 9; canals, 3. 
Ditches 
8 (46%) 
Includes one small stream in which water was very 
low and stagnant. 
Marsh, etc. 
6 (3-5%) 
Marshes, 5; water-logged field, 1. 
Receptacles 
2 (1-2%) 
Tin*, 1; concrete basin, 1. 
No details 
2 (1-2%) 
* On another occasion, numerous larvae were found in a petrol tin, cut to make an ablution 
basin, stranded in the mud at. the side of an Anopheline pool. 
The term “pools” refers principally to waters found in the farm-lands 
and for the most part lying in clayey soil. Many of these are natural but many 
undoubtedly are really waterholes of artificial origin having been dug in years 
past by farmers for use by cattle. These waterholes are usually circular, 
comparatively small, varying from about 20-60 feet in diameter, and are 
usually surrounded by pollard-willows. Their vegetation varies, some being 
clear of weeds, others with marginal weeds and algae more or less loosely 
distributed while others again have a dense mat of duckweed completely 
hiding the water. Moats with vegetation similar to that of pools are found 
round many of the farms and chateaux. The term “canal” is used in the 
strict sense of the word. In one case the map refers to certain water as a 
canal when the water really takes on the character of a narrow stream running 
fairly rapidly. This has been classified as a stream. 
The character of the Anopheline waters in regard to possible pollution 
from various sources has been noted nine times; on four occasions the water 
being described as “dirty”; once as “tea-coloured,” the reason for such a colour 
being unknown; once as “greenish with numerous larvae,” the green possibly 
due to cow manure and not to confervoids; once as “brown, not a likely 
place”; once as “poor quality, unusual place”; once as “containing some 
pollution.” In one case where the water was dirty the circumstances were 
exceptionally interesting. The pool in question was circular and about 60 feet 
in diameter, with many high sedges and a certain amount of duckweed at 
the margin. The water was black and turbid. Into one region ran the effluent 
of the inefficient soakage pit of a hospital bath-room, the effluent water being 
still soapy. Opposite this the pool drained into a narrow channel running 
through a culvert. Altogether a most unlikely spot for Anophelines! But 
near the entrance to the culvert both Anopheline and Culicine larvae were 
taken. The Anophelines did not show any unusual features but the Culicines 
presented a remarkable appearance as if they were covered with a white 
fungoid-like growth. This was probably due to the soap suds from the effluent. 
In another instance larvae were found in a small marginal patch of water 
surrounded by the marginal grass of a pool reddened by the rust of ration 
