ON ANNELIDA. 
117 
mation of the rings of their body, a part of which is more or 
less fastened to the soil by means of little hooks, and that in 
all directions. They doubtless walk more generally forward, 
but they can likewise move a little in a contrary direction. 
For entering the earth they always use the upper lip, which 
they contract, so as to give it solidity, and a terebrant form, 
but they never can perform this operation, except in a very 
loose and humid soil. The canals which they form in the 
earth, have always at least a double issue, one by which 
they enter and another by which they come forth. It is by 
the first that they eject in a vermicular form, the earth which 
they have swallowed in excavating their galleries, and they 
issue forth through the other. To ascend thus in their hole 
it appears that they make a little use of their spines. It is 
generally supposed that these animals feed only upon the 
animal and vegetable substances found in the earth which 
they traverse. But it appears that they join with those 
evident portions of organized bodies. It is quite certain that 
thelumbrici seek, in preference, unctuous soils, such as the holes 
where dung is deposited, the strata of our gardens, &c. 
Although these animals are really endowed with herma- 
phrodism, that is to say, they have both sexes at once, it 
does not appear to be complete, but the above approximation 
of two individuals is necessary for reproduction, without, 
however, any reciprocal penetration of an exciting organ. It 
is at the commencement of the spring that coupling takes 
place, and this always occurs during the night, and half out 
of the ground. The two individuals adhere so closely toge- 
ther, by a sort of agglutination of the enlarged ring, that they 
sooner suffer themselves to be crushed than separated. 
Montegre tells us, however, that this adherence is not so 
great as to prevent the animals from sinking into their hole, 
on the least sensation of approaching danger. At the end of 
a space of time of greater or less duration, but the exact 
