180 NATURAL HISTORY OF WASPS. 
female; besides, from his smaller size, and from his 
never being encumbered with the internal burden of 
a family, bemg much harder to catch. But it is the 
Vfemale mosquito and the female horse-fly only which 
bite. 
To procure a sting and all its appendages for 
examination, the best way is, as before, to press the 
abdomen of a recent specimen till the sting, and the 
muscular bulb to which itis attached, protude. Now, 
grasp the sting at its root with a pair of forceps, and 
draw it gently out, still keeping up the pressure. By 
this means we may secure the sting, the bulbous mass 
which moves it, and the poison bag, all together. As 
with regard to the ovaries, it is best to secure as 
many specimens of stings, and of as large a size, as we 
can, and set them aside in glycerine against a leisure 
afternoon. They will need, however, very little dis- 
section. Under a low power of the microscope, 
brightly illuminated on a black back-ground, the chief 
anatomical characters will be readily made out. 
And first of the sting itself. This consists of two 
very fine triangular bristles, presenting on the outer 
side a sharp edge finely serrated at the point, and 
on the inner side a flat channelled surface, where they 
le in juxta-position, along the middle line, like two 
bayonets laid together. These are the barbs. The 
scabbard, in which they slide, is a flat horny piece of 
considerable strength which most people, without a 
microscope, would take for the sting. It is connected 
at its inner end with the muscular bulb, and has its 
edges turned over to form guides for the barbs. It 
is nearly straight in the workers, but strongly curved 
in the females, and tapers towards its free end. The 
