THE TACHINADiE. 
613 
Most insects are hatched from eggs which are laid by the 
mother on the substances that are to serve for the food of 
her young. Some flesh-flies produce their young alive, or 
already hatched, and drop them on the dead and putrefying 
animal matter, which they are to consume and remove in 
the shortest possible time. An exception from the usual 
course among insects appears therefore to have been made 
in favor of these viviparous flesh-flies, to enable their young 
promptly to perform their appointed tasks. These insects 
produce an immense number of young, as many as twenty 
thousand having been observed by Reaumur in a single fly.* 
Our largest viviparous flesh-fly is the Sarcophaga Georgina 
of Wiedemann. It appears towards the end of June, and 
continues till the middle of August, or perhaps later. Its 
face is silvery white, and there is an oblong square black 
spot between the eyes, which are copper-colored. The tho- 
rax is light gray, with seven black stripes upon it. The 
hind body is nearly conical, has the lustre of satin, and is 
checkered with square spots of black and white, shifting or 
interchanging their colors according to the light wherein 
they are seen. The legs are black, and the hindmost pair 
are very hairy in the males. The female is about half an 
inch long ; the male is rather smaller. In the Sarcophagans, 
or flesh-eaters, as the name implies, the bristles on the an- 
tennae are feathered. 
The flies that abound in stables in August and September, 
and sometimes enter houses on the approach of rain, might 
be mistaken for house-flies, were it not for the severity of 
their bites, which are often felt through our clothing, and 
are generally followed by blood. Upon examination they 
will be found to differ essentially from house-flies in their 
proboscis, which is very long and slender, and projects hori- 
zontally beyond the head. The bristles on their antennas 
are feathered above. Cattle suffer sorely from the piercing 
bites of these flies, and horses are sometimes so much tor- 
* Mcmoires, Vol. IV. p. 417. 
