104 NATURAL HISTORY 



bably they bite every one, but the bite is insensible to some. I once 

 supposed that they did not bite me, but I now suppose they do. Going 

 to bed at night I have observed them marching down the curtains and 

 head of the bed : such when I caught and killed had no blood in them. 

 In the morning I have observed them marching back, and all such I 

 have found full of blood ; and in a very large one which had got under 

 my shirt at the shoidder I felt a something move, which I rubbed with 

 my hand on the outside of my shirt, and immediately found something- 

 wet ; and when I took off my shirt I found it was a very large bug. 

 The shirt was stained for some breadth with blood, and yet no marks 

 could be observed anywhere on the skin. The bugs I caught in the 

 evening had no smell, when killed ; which made me suppose that they 

 had smell only when full of blood. I next killed them when full of 

 blood ; and then they also had no smell. This was in the month of 

 August. The question now is, at what time do they emit the peculiar 

 odour ? 



Of the External Characters of Insects. 



The flying insect is, in common, made up of three parts, the ' head,' 

 the trunk or 'chest,' and the 'abdomen.' But in some the chest is com- 

 posed of two parts, which in such makes the whole body to be composed 

 of four parts. The common fly of all kinds, the Musea (Eristalis) tenax, 

 all of the bee-tribe, have the chest divided into two. 



All of the flying-kind have six legs, which arise from the chest 1 ; and 

 in those where the chest is made up of two parts, the anterior part is 

 smaller than the other, and it gives rise to the two fore legs. 



Of the Senses of Insects. 



It is more than probable that insects have all the five senses. We 

 know that they see, that they feel and that they hear ; for thunder, or 

 the firing of a gun, or the ringing of a gong, or of a large brass kettle, 

 will frighten bees. They certainly have taste ; and it is most probable 

 they have smell ; for I think that I have led a silk- worm to different 

 parts of a table by drawing a mulberry leaf before it ; and, by shifting 

 the leaf and placing it behind it, the worm has turned : but how far all 

 this might be accident I will not pretend to determine. Whether the 

 whole of that tribe are endowed with the five senses, is not easy to 

 determine : it certainly is not a reason why the whole should have them, 

 because one or more have ; for, in the most perfect animals, we find one 



1 [This applies to all true inseel -. j 



