352 
NATURAL HISTORY. 
a glass vessel, with air sufficient to keep it alive, shall pro- 
duce young which also, when separated from each other, 
shall be the parents of a numerous progeny. Thus, down 
for five or six generations, do these extraordinary animals 
propagate, without any congress between the male and fe- 
male; but in the manner of vegetables, die young bursting 
from the body of their parents, without any previous impreg- 
nation. At the sixth generation, however, their propagation 
stops, the gnat no longer produces its like, from itself alone, 
but it requires the access of the male to give it another suc- 
cession of fecundity. 
The gnat of Europe gives but little uneasiness; it is some- 
times heard to hum about our beds at night, and keeps oft 
the approaches of sleep by the apprehension it causes ; but 
it is very different in the ill-peopled regions of America, 
where the waters stagnate, and the climate is warm, and 
where they are produced in multitudes beyond expression. 
The whole air is there filled with clouds of these famished 
insects ; and they are found ofall sizes, from six inches long, 
to a minuteness that even requires the microscope to have 
a distinct perception of them. The warmth of the mid-day 
sun is too powerful for their constitution; but when the 
evening approaches, neither art nor flight can shield the 
wretched inhabitants from their attacks ; though millions 
are destroyed, still millions more succeed, and produce 
unceasing torment. 
The native Indians, who anoint their bodies with oil, and 
who have from their infancy been used to their depredations, 
find them much less inconvenient than those who are newly 
arrived from Europe ; they sleep in their cottages covered 
with thousands of the gnat kind upon their bodies, and yet 
do not seem to have t heir slumbers interrupted by these 
cruel devourers. If a candle happens to be lighted in one of 
those places, a cloud of insects at once light upon the. flame, 
and extinguish it ; they are therefore obliged to keep their 
candles in glass lanterns ; a miserable expedient to prevent 
an unceasing calamity ! 
