45S 
FLEA. 
} 
The history of this familiar insect does not appear 
to have been fully understood till towards the de- 
cline of the sixteenth century, when the observa- 
tions of Leewenhoek and others were directed to 
it. It is believed however that the first person 
who investigated all the changes of the animal, 
from the egg to the perfect Flea, was Signior 
Diacinto Cestone, an Italian, who communicated 
the account to the Royal Society of London. This 
was published in the HQth Number of the Philo- 
sophical Transactions, accompanied by figures, 
which though not conducted with the extreme 
accuracy which distinguishes the engravings of 
Roesel and some others, are yet sufficient to give 
a pretty clear idea of the egg, larva, &c. 
Among the chief singularities observable in the 
structure of the Flea may be noticed the extra- 
ordinary situation of the first pair of legs, which 
instead of being placed beneath the thorax, as in 
most other insects, are situated immediately be- 
neath the head: the antennas are short, hairy, and 
consist of five joints; and at a small distance be- 
neath these is placed the proboscis, which is strong, 
sharp-pointed, tubular, and placed between a ])air 
of jointed guards or sheaths, which are still fartiier 
strengthened at the base by a pair of pointed 
scales: the eyes are large, round, and black. The 
general appearance of the animal is too well known 
to require particular description: it may only be 
necessary to observe that the male is considerably 
smaller than the female, with the back rather sink- 
ing than convex, as it always is in the female in- 
