474 OBSERVATIONS ON 



BOMBYLIU8 MEDIUS. 



THE Bombyliw medius is much about in March and the 

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

 hairy insect, like an bumblebee, 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 17 . 



MUSCLE FLIES. 



IN the decline of the year, when the mornings and even- 

 ings become chilly, many species of flies (Musca) 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 resist- 

 ance 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 



17 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. 



