94 THOMPSON YATES LABORATORIES REPORT 
Since the date* mentioned, Anopheles have been collected on four occasions 
from farms in North and Mid Cheshire. The Mid Cheshire farm is at a distance of 
about thirty-five miles from Liverpool, and here Anopheles maculipennis occurred in about 
the same number and in similar situations as in the North Cheshire farms. 
About twenty Anopheles were collected at each farm. In all these sites it 
was noted that the majority of the mosquitoes of the genus Culex- were found 
on the parts of the damp walls near the ground, while Anopheles were generally 
caught near the ceiling. During the coldest weather the attitude both of Culex 
and Anopheles was peculiar and characteristic. The under surface of the thorax 
and abdomen was applied closely to the wall, while the legs were stretched straight 
out almost at right angles to the body. The absence of the characteristic attitude of 
Anopheles (at an angle to the surface), and the fact that both Culex and Anopheles 
assumed the peculiar outstretched attitude, made it difficult at first sight to 
distinguish specimens of the two genera, especially since among the Culex were a 
species having wings spotted somewhat similarly to Anopheles ( Culex annulatus ) : 
but on closer inspection even in the position described, the characteristic angle, seen 
in side view, between the direction of the head and thorax and of the abdomen of 
Culex, served to distinguish the genera. In this peculiar attitude the mosquitoes 
were very difficult to rouse ; the mouth of a bottle could be easily placed over 
them without disturbing them, and in fact, one had to lift them on to their legs by 
the rim, and then no attempt was made to fly : they would crawl lazily along the 
neck of the bottle. How long these mosquitoes remain in this position during the 
winter months is not easy to determine, but it was noticed that many of the Culex on 
the damper patches were wholly or partially enveloped in a thick mould which had 
grown in and around their bodies, thus fixing them in the attitude described. On 
very cold days this attitude was observed even in the bottles in which the mosquitoes 
had been collected. On warmer days at the farms, and on taking the bottled 
mosquitoes into a warm room, they assumed their ordinary attitudes. 
It has been mentioned above that mosquitoes were not found, or only very 
rarely, in stables, pigsties, and henpens, etc., which were frequented by animals. 
Such places are generally comparatively dry, constantly disturbed, and warmed by 
the presence of horses and cattle at night. 
A number of the Anopheles collected by us have been kept in a damp cage in 
the animal house of the Thompson Yates laboratories, no food having been supplied ; 
only two of the number have died during the month we have kept them in this 
condition. There can, therefore, be no doubt that mosquitoes of both genera 
' hibernate ' during the winter months in England, and it seems certain that not 
only the adults but, from Dr. Wright's experiments, the larval forms also provide 
for the continuation of the species during the cold weather. 
It is of interest to note that among the numbers of mosquites of both genera 
collected by us a male was never found ; and, moreover, that all the females with 
