192 EYENIXGS AT THE MICROSCOPE. 



Tlie male Gnat presents in its antennae a pair of 

 plumes of equal beauty, but of a totally different char- 

 acter. Tlie pattern here is one of exceeding lightness 

 and grace, as you may see in this specimen. Each an- 

 tennte is essentially a very slender cylindrical stem of 

 many joints (about fourteen) ; at each joint springs out 

 a whorl of fine hairs of great length and delicacy, which 

 radiate in various directions (not, however, forming a 

 complete circle), curving upward like the outline of a 

 saucer, supposing the stem to be mserted into its centre. 

 The length of these hairs is so great that the diameter 

 of their sweep equals, if it does not exceed, the whole 

 length of the antenna. 



In the tribe of two-winged insects, which we term, 

 jyar excellence^ Flies {Muscadce)^ the antennae are of 

 peculiar structure. Tlie common House-fly shall give 

 us a good example. Here, in front of the head, is a 

 shell-like concavitv, divided into two bv a central ridge. 

 Just at the summit of this project are the two antennae, 

 originating close together, and diverging as they pro- 

 ceed. Each antenna consists of three joints, of which 

 the first is very minute, the second is a reversed cone, 

 and the third, which is large, thick, and ovate, is bent 

 abruptly downwards immediately in front of the ctm- 

 cavity. From the upper part of this third joint pro- 

 jects obliquely a stiff bristle or style, which tapers to a 

 fine point. It is densely hairy throughout ; and is 

 moi-e beset with longer hairs, on two opposite sides, 

 which decrease regularly in length from the base, mak- 

 ing a wide and pointed plume. 



Such arc a few examples of what are presumed to 

 be the ears of Insects ; let us now turn our attention 

 to their eyes. And we can scarcely select a more bril- 



