342 OBSERVATIONS ON 



the ichneumon applied her tail to him, and stung him with great 

 vehemence, so that he soon became dead and motionless. The 

 ichneumon then running backward drew her prey very nimbly 

 over the walk into the standing grass. This spider would be de- 

 posited in some hole where the ichneumon would lay some eggs ; 

 and as soon as the eggs were hatched, the carcase would afford 

 ready food for the maggots. 



Perhaps some eggs might be injected into the body of the 

 spider, in the act of stinging. Some ichneumons deposit their 

 eggs in the aurelia of moths and butterflies. 



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 an 

 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. 



MUSCLE. FLIES. 



In the decline of the year, when the mornings and evenings be- 

 come 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 



