



























DIPTERA. 41 
know that there are six. Réaumur, as also Leuwenhoek, thought 
he saw two in the form of a sword blade with three edges. These 
have the points reversed, and are serrated on the convex side of 
the bend (Fig. 25). To form an idea of the shape of the other 
points, the reader should look at Figs. 26 and 27. He will then 
see that the gnat’s sting is a sword in miniature. 
The prick made by so fine a point as that of the sting of the 
| gnat, ought not to cause any pain. ‘The point of the finest 
needle,’ says Réaumur, ‘“‘compared to 
the sting of the gnat, is the same as the 
point of a sword compared to that of the 
needle.” How is it then that so small 
a wound does not heal at once? How 
is it that small bumps arise on the part 




that is stung? The fact is, that it is not * 
only a wound, but it has been imbued with is 
an irritating liquid. ries. 2 : 
This liquid may be seen to exude, under Lancets of the Gnat. by 
different circumstances, from the trunk of the gnat, like a drop of Hy 
very clear water. si 
Réaumur sometimes saw this liquid even in the trunk itself. we 
“There is nothing better,” he observes, “to prevent the bad — 
effects of gnat bites than at once to dilute the liquid they is 
have left in the wound with water. However small this wound . 
may be, it will not be difficult for water to be introduced. By - 
rubbing, it will be at once enlarged, and there is nothing to do 2 
but to wash it. I have sometimes found this remedy answer i 
very well.” 2 
The gnat is not always in the form of a winged insect, greedy 3 
for our blood. There is a period during which they leave us in 
repose. This is the larva period. It is in water, and in stagnant 
water in particular, that the larva of the insect which occupies 
our attention is to be found. It resembles a worm, and may be 
found in ponds from the month of May until the commencement 
of winter. 
If we desire to follow the larva of the gnat from the 
beginning, we have only to keep a bucket of water in the open 
air. After a few days this water will be observed to be full 

