366 
NATURAL HISTORY. 
perceived a variety of kinds, almost equal to that variety of 
productions which these little animals are seen to form. 
He has been thus able to perceive and describe fifty differ- 
ent kinds, each of which is seen to possess its own peculiar 
mode of construction, and to form a coraline that none ot 
the rest can imitate. It is true, indeed, that on every cora- 
line substance there are a number of polypi found, no way 
resembling those which are the erectors of the building. 
But, in general, the same difference that subsists between 
the honeycomb of the bee, and the paper-like cells of the 
wasp, subsists between the different habitations of the coral- 
making polypi. 
With regard to the various forms of these substances, they ' 
have obtained different names from the nature of the animal 
that produced them, or the likeness they bear to some well- 
known object, such as coralines,fungimadripores, sponges, 
astroites, and keratophytes . 
When examined chemically, they all discover the marks 
of animal formation ; the corals, as was said, dissolve in 
acids, the sponges burn with an odour strongly resembling 
that of burnt horn We are left somewhat at a loss with 
regard to the precise manner in which this multitude of cells, 
which at last assume the appearance of a plant or flower, 
are formed. If we may be led in this subject by analogy, it 
is most probable, that the substance of coral is produced in 
the same manner that the shell of the snail grows round it ; 
these little reptiles are each possessed of a slimy matter, 
which covers its body, and this hardening, as in the snail, 
becomes an habitation exactly fitted to the body of the ani- 
mal that is to reside in it ; several of these habitations being 
joined together, form at length a considerable mass, and, as 
most animals are productive in proportion to their minute- 
ness, so these multiplying in a surprising degree, at length 
form those extensive forests that cover the bottom of the 
deep. 
