ORDER VII.—TWO0-WINGED INSECTS, OR FLIES. 307 
by small ichneumons. These maggots have a skin as strong 
almost as parchment, two horny hooks near the head, as in 
the meat-fly, with which they work the cheese and effect 
their jumping motions. In the performance of this latter 
feat these disgusting little creatures far excel man or any 
animal whatever. One of them not longer than a quarter 
of an inch will jump up into the air six inches—at least 
twenty-four times its length. How strange that we can 
look upon the wonderful feats like this, performed by in- 
significant little insects, without being amazed at the im- 
mense effort and agility displayed! It is only because we 
do not think of them sufficiently deep, and compare their 
motions with our own. The step of a fly is so small in 
comparison with that of a man, we do not think to com- 
pare the number or the speed of their steps to those of man, 
and yet the latter is the proper light by which to observe 
them. 
M. Delisle once watched a fly, only as large as a grain of 
sand, which ran three inches in half a second, and in that 
space of time made the enormous number of five hundred 
and forty steps. Ifa man were to be able to walk as fast, 
in proportion to his size, supposing his step to measure two 
feet, he would, in the course of a minute, have run upward 
of twenty miles—a task far surpassing our express railroad 
engines, or even the famous “Seven League Boots” record- 
ed in the nursery fable. So, in jumping or leaping, these 
insects display astonishing power. Some spiders leap a 
couple of feet upon their prey. The insect called the 
“frog-hopper” can leap more than two hundred and fifty 
times its own length. A flea can leap two hundred times 
its own length; so also can the locust. If a man were six 
feet long, and could leap as high and as far as one of these 
insects, he might stand near the custom-house in New 
York, leap up into the air over the top of Trinity Church 
spire, and alight in Greenwich Street; which would be 
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