2 
times it may be picked up readily and is very subject to the attacks of 
a fungous disease which causes it to die upon window panes, surrounded 
by a whitish efflorescence. Occasionally this fly occurs in houses in 
such numbers as to cause great annoyance, but such occurrences are 
comparatively rare. 
A fourth species is another stable fly, known as Muscina stabulans 
Fall. (fig. 3), a form which almost exactly resembles the house fly in 
general appearance, and which does not bite as does the biting stable 
fly. It breeds in decaying vegetable matter and in excrement. 
Several species of metallic greenish or bluish flies are also occasion- 
ally found in houses, the most abundant of which is the so-called blue- 
bottle fly (Calliphora erythrocephala Meig.). This insect is also called 
the blow-fly or meat-fly and breeds in decaying animal material. A 
smaller species, which may be called the small blue-bottle fly, is Phormia 
‘ 
Fia. 2.—Stomozys calcitrans: Adult, larva, puparium, and details. All enlarged (author's 
illustration). 
terrenove Desv. (fig. 4); and a third, which is green in color and about 
the size of the large blue-bottle, is Lucilia cwsar L. (fig. 5). 
There is still another species, smaller than any of those so far men- 
tioned, which is known to entomologists as Homalomyia canicularis L., 
sometimes called the small house fly. A related species, H. brevis 
Rond., is shown in figure 6. H. canicularis is distinguished from the 
ordinary house fly by its paler and more pointed body and conical 
shape. The male, which is much commoner than the female, has large 
pale patches at the base of the abdomen, which are translucent when 
the fly is seen on a window pane.. It is this species that is largely 
responsible for the prevalent idea that flies grow after gaining wings. 
Most people think that these little Homalomyias are the young of the 
larger flies, which, of course, is distinctly not the case. 
Still another fly, and this one is still smaller, is a jet-black species 
known as the window fly (Scenopinus fenestralis L.), which in fact has 
