Of the Flea. £9 
Hies, which they greedily fuck. In eleven days they come 
to the full perfection of the reptile Itate, when the mag¬ 
got fpins its bag, and in four days more changes into a 
chryfalis; after lying in which condition nine days, it 
becomes a perfect flea. It is then immediately capable of 
coition, and in three or four days lays eggs; fo that in m 
twenty-eight days, a flea may come from its egg, and 
propagate its kind; and their vafl: increafe will not feem 
fo great a wonder if we confider, that from'March to 
.December there may be feven or eight generations of 
them; after having laid their eggs they foon die, as all 
creatures do that undergo fuch like changes. 
If you keep fleas in fuch a glafs tube,, as is before de- 
fcribed, fo as to admit frefli air, their feveral aCtions may 
be obferved, and particularly their way of coupling, which 
is performed tail to tail. The female (which is much the 
larger) Handing over the male: they will alfo be feen to 
lay their eggs, not all at once, but ten or twelve in a 
day for feveral days fucceflively 3 which eggs hatch in the 
fame order. 
A difle&ion of the flea may be effeCled in water, the R 
fiomach and bowels, with their periflraltic motion, may 
plainly be diflinguifhed, and alfo the teftes and penis, 
together with veins and arteries, minute beyond con¬ 
ception. Mr. Leeuwenhoek affirms, that he has likewife 
difcovered innumerable animalcules, fhaped like ferpents* 
in the femen mafculinum of a flea, 
** Arc, Nat, Tom. iv. p. 3z;. *» Ibid* P* 33£» 
Of 
