THE GNAT AND TIPUHA. 
351 
that the extremity of it can scarcely be discerned through the 
best microscope that can be procured. That part which is at 
first obvious to the eye, is nothing but a long scaly sheath 
under the throat. At near the distance of two thirds of it 
there is an aperture, through which the insect darts out four 
stings and afterwards retracts them. One of which, however 
sharp and active it may be, is no more than the case in which 
the other three lie concealed, and run in a long groove. The 
sides of these stings are sharpened like two-edged swords; 
they are likewise barbed, and have a vast number of cutting 
teetli towards the point, which turns up like a hook, and is 
fine beyond expression. When all these darts are stuck into 
the flesh of animals, sometimes one after another, and some- 
times all at once, the blood and humours of the adjacent parts 
must unavoidably be extravasated ; upon which a tumour 
must consequently ensue, the little orifice whereof is closed 
up by the compression of the external air. When the gnat, 
by the point of her case, which she makes use of as a tongue, 
has tasted any fruit, flesh or juice, that she has found out ; if 
it be a fluid, she sucks it up, without playing her darts into 
it; but in case she finds the least obstruction by any flesh 
whatever, she exerts her strength, and pierces through it if 
possibly she can. After this she draws back her stings into 
their sheath, which she applies to the wound in order to ex- 
tract, as through a reed, the juices which she finds inclosed. 
This is the implement with which the gnat performs her 
Work in the summer, for during the winter she has no man- 
ner of occasion for it. Then site ceases to eat, and spends 
all that tedious season either in quarries or in caverns, which 
she abandons at the return of summer, and flies about in 
search after some commodious ford, or standing water, 
where she may produce her progeny, which would be soon 
Washed away and lost, by the too rapid motion of any run- 
ning stream. The little brood are sometimes so numerous, 
that the very water is tinged according to the colour of the 
species, green if they be green, and of a sanguine hue if 
they be red. 
These are circumstances sufficiently extraordinary in the 
life of th is little animal, but it offers something still more 
curious in the method of its propagation. 
However similar insects of the gnat kind are in their ap- 
pearance, yet they differ widely from each other in the 
manner in which they are brought forth, for some are pro- 
duced from eggs, and some are viviparous, and come forth 
"i their most perfect form. 
A gnat separated from the rest of its kind, and inclosed in 
