THE LYTHOPHYTES AND SPONGES. iHS 



which are formed by snails, mussels, and oysters, these coraliiie 

 substances effervesce with acids ; and may therefore well be 

 supposed to partake of the same animal nature. But iVIr Ellis 

 went still farther, and examined their operations, just as they 

 were begitming. Observing an oyster-bed which had been for 

 some time neglected, he there perceived the first rudiments of a 

 coraliiie plantation, and tufts of various kinds shooting from dif- 

 ferent 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 shown no signs of life, expanding themselves 

 in every direction, 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 ob- 

 jects of curiosity. For this purpose, he poured, by slow de- 

 grees, an equal quantity of boiling water into the vessel of 

 sea-water in which they were immersed. He then separated 

 each polypus with pincers from its shell, and plunged each 

 separately into small crystal vases, filled with spirit of wine 

 mixed with water. By this means the animal was preserved 

 entire, without having time to contract itself, and he thus per- 

 ceived a variety of kinds, almost equal to that variety of produc- 

 tions which these little animals are seen to form. He has been 

 thus able to perceive and describe fifty different kinds, each of 

 which is seen to possess its own peculiar mode of construction, 

 and to form a coraline that none of the rest can imitate. It is 

 true, indeed, that on every coraline substance there are a num- 

 ber of polypi found, no way resembling those which are the 

 erecters of the building : these may be called a vagabond race of 

 reptiles, that are only intruders upon the labours of others, and 

 that take possession of habitations, which they have neither art 

 nor power to build for themselves. 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 Ihcm, or the likeness they bear to some well-known 



