OBSERVATIONS ON INSECTS AND VERMES. 413 
There are many instances of the great service these little insects 
are to mankind in reducing the number of noxious insects, by 
depositing their eggs in the soft bodies of their /arvv@, but none 
more remarkable than that of the ichneumon 7#pu/@, which pierces 
the tender bodies and deposits its eggs in the Zarva of the Tzpula 
tritici, an insect, which, when it abounds greatly, is very prejudicial 
to the grains of wheat. This operation I have frequently seen it 
perform with wonder and delight.— MARKWICK. 
BOMBYLIUS MEDIUS. 
The Bombylius medius is much about in March and the beginning 
of April, and soon seems to retire, It is an hairy insect, like a 
humble-bee, but with only two wings, and a long straight beak, 
with which it sucks the early flowers. The female seems to lay its 
eggs as it poises on its wings, by striking its tail on the ground, 
and against the grass that stands in its way, in a quick manner, for 
several times together.— WHITE. 
I have often seen this insect fly with great velocity, stop on a 
sudden, hang in the air in a stationary position for some time, and 
then fly off again ; but do not recollect having ever seen it strike 
its tail against the grcund, or any other substance.—MARKWICK. 
MUSC:.—FLIES. 
In the decline of the year, when the mornings and evenings 
become chilly, many species of flies (A/usc@) retire into houses, 
and swarm in the windows. 
At first they are very brisk and alert; but as they grow more 
torpid, one cannot help observing that they move with difficulty, 
and are scarce able to lift their legs, which seem as if glued to the 
glass; and by degrees many do actually stick on till they die in 
the place. 
It has been observed that divers flies, beside their sharp hooked 
nails, have also skinny palms, or flaps to their feet, whereby they 
are enabled to stick on the glass and other smooth bodies, and to 
walk on ceilings with their backs downward, by means of the 
pressure of the atmosphere on those flaps; the weight of which 
