234 THOMPSON YATES LABORATORIES REPORT 
water, often quickly drying up in the hot sun, occasionally so replenished by rain 
showers as to be for a period more or less full of water ; some, however, deep, and always 
containing water. They also serve in many places as duck ponds. They were 
examined time after time but no larvae found, although a few Anopheles adults could 
always be procured in the houses in the neighbourhood. It has been surmised that 
the chief breeding-places of Anopheles in these parts are the pools on the river banks 
above mentioned, and that during the greater part of the wet season Anopheles do not 
breed copiously. Whether this is so, only careful observation during the dry season 
can determine. 
It is to be remarked that Anopheles larvae were never found in the bush or at 
any great distance from human habitation. The greatest distance observed was 
under half a mile. Near Old Calabar, at a point some two or three miles in the 
bush, is a spring, which is intended to be utilised for the water supply of Old 
Calabar. Engineering operations have already been commenced, and a well bricked 
in to the depth of some eight feet. The immediate neighbourhood of the well is 
flooded. Innumerable Anopheles larvae were found here. The spring occurs at the 
bottom of a natural depression in the surface, some eighty or a hundred feet deep, 
which is surrounded with thick forest growth, and approached only by narrow foot- 
paths. The only habitations in the neighbourhood are a small hut on the edge of 
the depression, and another one about half a mile along one of the paths. Two 
native villages occur at a distance of about a mile. The spring is visited daily by 
scores of natives for drinking water, and a number of labourers are at present carry- 
ing out engineering operations. The occurrence of such an extensive breeding-place 
away from any large collection of natives is extremely remarkable. 
The fact that Anopheles larvae are occasionally found in those sites which are 
generally occupied by Cukx, namely, broken bottles, calabashes, iron pots, barrels, etc., 
tends to suggest that in places where the natural breeding-places of Anopheles become, 
either from scarcity of rain or in consequence of artificial destructive means, very 
scarce, Anopheles will make use of any available water which will last sufficiently 
long for the purpose of laying their eggs. The conditions above mentioned were met 
with principally in the middle of Bonny native town, where the usual breeding-places, 
the dug-out canoes, were at some distance, and any puddle which might form on the 
narrow footpaths and streets was continually disturbed by the trampling of passers-by. 
Breeding-places of Cukx. — These consisted of sites similar to those already 
described by many authors as occurring in the immediate proximity of dwelling- 
houses in the tropics — pots, bottles, tins, cans, calabashes, tubs, barrels, iron vessels, 
rain tubs, water tanks, pools, puddles, canoes, cocoanut husks, the hollows at the 
junction of the leaves and stems of the banana tree — and any place where water 
lodges for a few days. Larvae were found in fire-buckets and other vessels inside 
houses of Europeans. 
