6 
chance, however, of obtaining some information upon this subject, 
it must be obvious, will be yielded by making those animal substances 
the first objects of our inquiry, which were originally the most simple 
in their constitution. Such, it must be admitted, are corals ; the sim- 
plicity of the composition of which has been made known to us by 
the interesting experiments of Mr, Hatchett. 
But, although it is intended, for this reason, to adopt the order of 
Wallerius, so far as to commence the animal fossils with the corals, 
and then to proceed upwards in the scale of animation, it is not, how- 
ever, proposed to separate, with this author, these bodies from the 
class of worms, (vermes, Linn.) It is, on the contrary, intended still 
to consider corals in their fossil state, as forming different genera and 
species, in the order of zoophytes, in the class of vermes. 
Of the origin of coralloids, as the fossil corals are sometimes termed, 
it will not be necessary to say much at the present day, when so many 
proofs have been adduced of their having derived their origin from 
real corals, which have been disposed in such situations as have con- 
duced to the changes which they have undergone. The more ancient 
notions of their having proceeded from the operations of a vis plastica, 
vis formativa, &c. need no farther notice, than to observe, that even 
in the last century, Dr. Woodward admitted it to form a part of the 
hypothesis, by which he proposed to account for the origin of various 
secondary fossils, and especially of coralloids. 
The original hardness of many of the zoophytes led to a considerable 
degree of confusion ; since many of the earlier naturalists, not per- 
ceiving the actual change which the fossil bodies of this kind had 
undergone, made no distinction ; but considered these bodies as ex- 
isting in their original natural state. But, as the science advanced, 
the circumstance of their having been found in subterraneous situa- 
tions called for explanation ; nor would fanciful and unfounded suppo- 
sitions be admitted. It was no longer sufficient to say, with Encelius, 
that they were formed by the indurating power of the air ; or that they 
