350 
C. GORDON HEWITT. 
suburban houses and country houses and cottages, I find that 
in the former it is by far the commonest house-fly. But 
whei’eas M. domes tica may be almost the only species in 
warm places where food is present, such as restaurants and 
kitchens, in other rooms of houses Homalomyia cani- 
cularis, the small house fly, increases in proportion and 
often predominates ; occasionally one may find it to be 
commoner than M. domestica. In country houses the 
proportions vary by the intrusion of Stomoxys calcitrans, 
which I have often found to be the dominant species. In a 
certain country cottage, out of the several hundreds captured, 
S. calcitrans formed 50 percent, of the total, the rest being 
chiefly H. canicular is together with An tho myia radicum, 
whose lai’vae, as I have shown (1907), breed in horse-manure 
with those of M. domestica. The following records taken 
from a “ fly census ” that was made in 1907 may be taken as 
illustrative of the proportional abundance of the different 
species in different situations ; although the numbers of these 
records are small the pi-oportions are more obvious. 
M. 
domestica. 
H . c anicu- 
laris. 
Other species. 
Restaurant, Manchester 
18G9 
14 
2 (M. stabulans. 
C. ery throcephala). 
Kitchen, detached suh- 
1 
urban house (six records). 
Lancashire 
581 
265 
14 
Kitchen, detached sub- 
urban house in Manchester 
682 
7 
14 
Stable, suburban house 
22 
153 
14 
(12. S. calcitrans). 
Bedroom, suburban house . 
1 
33 
4 (M. stabulans). 
Out of a total of 3856 flies caught in different situations, 
such as i-estaurants, kitchens, stables, bedrooms and hotels, 
87’5 per cent, were M. domestica, ITS per cent. H. canicu- 
laris, and the rest were other species such as S. calcitrans, 
Muscina stabulans, C. ery throcephala, and Antho- 
myia radicum. These figures are comparatively small, but 
