588 
SNAIL. 
procured, and part of their shells broken off* without 
bruising the animals. In this state they were en- 
closed under glasses, and accommodated with a pro- 
per quantity of earth and green leaves. That part 
of the body which became visible by the fracture 
of the shell, was immediately covered with a kind 
of froth that flowed through all the pores, and was 
soon succeeded by a second evacuation, which gra- 
dually raised the first to a level with the old shell. 
That this juice flows from the body of the animal, 
and not from the extremities of the adjoining shell, 
is rendered sufficiently clear by the following ex- 
periment. The little skin which grows under the 
shell of a hen’s egg, was carefully inserted between - 
the body of the snail and the extremity of the frac- 
ture. If the shell had then contributed to its own 
reparation, the juice that would have flowed from it 
must certainly have been shed over the little skin, 
and had covered it in proportion as the cavity closed. 
On the contrary, if the fluid proceeded from the 
body of the snail, this skin would have prevented 
its effusion to the shell, and in this case, the juice 
would settle between the cuticle and the body of the 
animal; which, in reality, happened to be the fact. 
Although this experiment accounts for the for- 
mation of the shell in a satisfactory manner, yet 
another difficulty remains to be cleared up. If the 
shells are formed in the manner we have described, 
and the fractures they receive are repaired by a mat- 
ter that passes through the very same perforations 
that originally ejected the substance of the shattered 
