THE LIVING WORLD, 
255 
in the hides of oxen. The horse-fly proper (gastrophilus equi) attaches a single 
egg to a single hair of the horse. In its larval period it feeds upon the stomach of 
the horse, and exhibits a strange power of apparent suspension of respiration when 
the air is unfit for 
its use. At the end 
of ten months the 
larvae, being ready 
for metamorphosis 
into pupae, are ejected 
with the excrement 
of the horse, and re¬ 
turn like a fright¬ 
ened child to the 
bosom of Mother 
Earth. 
The House-Fly 
is ash-colored and 
has a black face, 
whose sides are yel¬ 
low. The forehead 
has yellowish black 
stripes. The thorax 
is blackened; the 
abdomen pale be¬ 
neath and yellow on 
the sides. The feet 
are black, and the 
wings transparent. 
The proboscis is a 
separate organ, thick, 
membranous, and 
ending in two lobes, 
which form from the 
lower lip and the 
mandibles a blade¬ 
like instrument. 
Beginning life as a 
white maggot, upon 
approaching the 
chrysalis, or pupal 
stage, it shortens its 
body and hardens 
its skin, and for the 
first time develops 
a head and legs, 
and replaces its rudi¬ 
mentary month by 
a true mouth. Filth 
different to the wide 
metamorphosis oe the dragon FEY. (. Libella depressa.) 
to them the staff of life, and they seem to 
differences between sugar and tobacco spittle. 
be in- 
Tliis 
