302 NORTH AMERICAN INSECTS. 
where the sun shines brightly. The female is larger than 
the male ; and when about ready to lay her eggs, the hind 
body becomes so transparent that the eggs are seen through 
it on both sides. The development of the egg may best be 
observed by putting moistened wheat or barley into a glass 
vessel, and leaving it until it is spoiled and has become 
black, when three or four eggs will be seen on the grains 
and may be closely watched. ‘These eggs are cylindrical in 
form, pointed at one end, and its surface shines like mother- 
of-pearl. After about twenty-four hours the maggot leaves 
the egg, and grows for two weeks, until it is about three 
lines long, when it is metamorphosed into a cylindrical red- 
brown pupa, from.which the perfect fly, with its hairy gray 
feet, issues in about two weeks. These hairy feet are of 
great use to this little insect, and assist in keeping it nice 
and clean, because it uses them as brushes, with the hind 
ones to brush the dust from its wings, and with the fore 
feet wiping its face and eyes. 
As these flies torment man, they are in the same ratio 
themselves tormented by very small mites, which in large 
numbers move between their hairs, and which they can not 
get rid of by any means. We resort to many measures to 
abate the nuisance of flies, and there are many mixtures 
recommended as sure death to these our little tormentors; 
but it is doubtful, with all of them, whether they do not at- 
tract the flies in greater proportion than they destroy them. 
Dr. Harris says: “If a plateful of strong green tea, well 
sweetened, be placed in an outer apartment, accessible to 
flies, they will taste of it, and be killed thereby as soon as 
by the most approved fly-poison.”’ 
The Merat-rry (Musca vomitoria) is about half an inch 
long, and two lines thick, hairy, black, and has a shining 
blue hind body. ‘This insect is remarkable for its extraor- 
dinary sense of smell, and hence a piece of meat can hardly 
be placed out of its reach; for, unless very securely closed 
