ARTICULATA—LEECH. 777 
torward the hinder part; in this manner it moves onward, not without great 
effort; but the eccasions for its progresssive motion are few. 
As it is designed for living under the earth, and leading a life of obscurity, 
so it seems tolerably adapted to its situation. Its body is armed with small, 
stiff, sharp burrs or prickles, which it can erect or depress at pleasure ; under 
the skin there lies a slimy juice, to be ejected as occasion requires at certain 
perforations, between the rings of the muscles, to lubricate its body, and 
faci\tate its passage into the earth. Like most other insects, it has breath 
ing holes along the back, adjoining each ring; but it is without bones, 
without eyes, without ears, and, properly, without feet. It bas a mouth, 
and also an alimentary canal, which runs along to the very point of the 
tail. In some worms, however, particularly such as are found ia the bodies 
of animals, this canal opens towards the middle of the belly, at some dis- 
tance from the tail. The intestines of the earth worm are always found 
filled with a very fine earth, which seems to be the only nourishment these 
animals are capable of receiving. 
The animal is entirely without brain; but near the head is placed the 
heart, which is seen to beat with a very distinct motion, and round it are the 
spermatic vessels, forming a number of tittle globules, containing a milky 
fluid, which have an opening into the belly, not far from the head ; they are 
also eften found to contain a number of eggs, which are laid in the earth, and 
are hatched in twelve or fourteen days into life, by the genial warmth of 
their situation. 
When the eggs are laid in the earth, which, in about fourteen days, as has 
been said, are hatched into maturity, the young ones come forth very small, 
but perfectly formed, and suffer no change during their existence: how long 
their life continues is not well known, but it certainly holds for more than 
two or three seasons. During the winter, they bury themselves deeper in 
the earth, and seem, in some measure, to share the general torpidity of the 
insect tribe. In spring, they revive with the rest of nature, and on those 
occasions a moist or dewy evening brings them forth from their retreats, for 
the universal purpose of continuing their kind. They chiefly live in a light, 
rich, and fertile sail, moistened by dews or accidental showers, but avoid 
those places where the water is apt to lie on the surface of the earth, or 
where the clay is too stiff for their easy progression under ground. 
Pe i BCH, 
From its uses in medicine, is one of those insects that man has taken care 
to propagate , but, of a great variety, one kind only is considered as services 
$8 
