INSECTS AND VERMES. 851 



BOMBYLIUS MEDIUS. 



THE Bomlylius medius is much about in March and the 

 beginning of April, and soon seems to retire. It is a 

 hairy insect, like an humblebee, 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. 1 



MUSCJE FLIES. 



IN the decline of the year, when the mornings and evenings 

 become chilly, many species of flies (Muscce) 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, besides their sharp 

 hooked nails, have also skinny palms, or flaps to their feet, 

 whereby they are enabled to stick on 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 they easily overcome in 

 warm weather when they are brisk and alert. But in the 

 decline of the year, this resistance becomes too mighty for 

 their diminished strength ; and we see flies labouring along, 

 and lugging their feet in windows, as if they stuck fast to 

 the glass, and it is with the utmost difficulty they can draw 

 one foot after another, and disengage their hollow caps 

 from the slippery surface. 



Upon the same principle that flies stick and support 



1 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 ground, or any other substance. MARKWICK. 



