OF LITHOPH YTES AND SPONGES. 
365 
soon expire when taken out of the sea, and our curiosity is 
at once stopped in its career by the animals ceasing to give 
any instance of their industry ; recourse, therefore has been 
had to other expedients, in order to determine the nature 
of the inhabitant, as well as the habitation. 
If a coraline plant be strictly observed while still growing 
in the sea, and the animals upon its surface be not disturbed, 
either by the agitation of the waters, or the touch of the ob- 
server, the little polypi will then be seen in infinite numbers, 
eacli issuing from its cell, and in some kinds, the head 
covered with a little shell, resembling an umbrella, the arms 
spread abroad, in order to seize its prey, while the hinder 
•part still remains attached to its habitation, whence it never 
wholly removes. By this time it is perceived that the number 
of inhabitants is infinitely greater than was at first suspected ; 
that they are all assiduously employed in the same pursuits, 
and that they issue from their respective cells, and retire 
into them at pleasure. Still, however, there are no proofs 
that those large branches which they inhabit are entirely 
the construction of such feeble and minute animals. But 
chemistry will be found to lend a clue to extricate us from 
our doubts in this particular. Like the shells which are 
formed by snails, muscles, and oysters, these coraline sub- 
stances effervesce with acids, and may therefore be supposed 
to partake of the same animal nature. But Mr. Ellis went 
still farther, and examined their operations, just as they 
were beginning. Observing an oyster-bed, which had been 
for s-ome time neglected, he there perceived the first rudi- 
ments of a coraline plantation, anti tufts of various kinds 
shooting from different parts of this favourable soil. It was 
upon these he tried his principal experiment. He took out 
the oysters which were thus furnished with coralines, and 
placed them in a large wooden vessel, covering them with 
sea-water. In about an hour he perceived the animals, 
which before had been contracted by handling, and had 
shewn no signs of life, expanding themselves in every direc- 
tion, and appearing employed in their own natural manner. 
Perceiving them therefore in this state, his next aim was to 
preserve them thus expanded, so as to be permanent objects 
of curiosity. For this purpose he poured, by slow degrees, 
an equal quantity of boiling water into the vessels of sea- 
water in which they were immersed, lie then separated each 
polypus with pincers from its shell, and plunged each sepa- 
rately into small crystal vases, filled with spirits of wine 
mixed with water. By this means, the animal was preserved 
entire, without having time to contract »tself, and he thus 
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