] 02 NATURAL HISTORY 



over them, they immediately draw in their belly under them, and rest 

 on the hack part of their belly, upright, with their trunk ready to 

 defend or attack ; and, if the finger comes within their reach, they im- 

 mediately lay hold of it and bite. 



They breathe air similar to other winged insects ; it is seen in the 

 abdomen. In those that have wings there is a good deal of oil or fat ; 

 for in dissecting them in water, a considerable number of small globides 

 were seen rising from them and floating on the surface of the water. 



When they have got their wings they still work, for I put some of 

 them into a glass with some earth, and they burrowed ; and I saw 

 them busy in going down their subterraneous cells and bringing up the 

 mould in their pincers. I also saw them carrying the egg or chrysalis 

 like the common wingless ant. 



Many of these flying ants are of a very pale brown. I suspect that 

 when they get their wings they cast off their ant-coat, and get a new 

 one, which is white at first, and becomes brown afterwards. 



Of the Musca [Eristalis] tenax. 



This fly lays its eggs on the dry sides of vessels, or cavities con- 

 taining putrid animal matter in a fluid form, or on substances projecting 

 above the surfaces of such fluids. I believe this is performed in the 

 month of June. 



The progress of hatching, the period of the maggot, and the continu- 

 ance in the chrysalis state, are all very short. My gardener caught 

 one about the beginning of June. I caught one on the 4th of April, 

 1790 : the winter had been remarkably mild. About the latter end 

 of June the young are coming forth, and then they are more in numbers. 

 In the months of July, August, and September they are in great 

 numbers. About the latter end of September they are getting into 

 houses, especially out-houses, half insensible. 



I caught one on the 20th of October, a female ; its stomach was full, 

 but it had no fat 1 . 



Of the Gnat \Culex pipiens]. 



This animal may be said to be an aquatic one while in the maggot 

 or second state. They live in the water till they go into the chrysalis 

 state ; yet I imagine they breathe air ; for, like the Musca tenax, 

 they keep the end of the tail afloat, which is their trachea ; but they 

 differ from the Musca tenax in having considerable progressive motion 

 in the water, although the power is seldom or ever used but when they 



1 [Hunt. Prep. No. 596.] 



