A'OL. XLVir.] PHILOSOPHICAL TRANSACTIONS. '2^5 



own coasts, and usually called a prule) the animal of the madrepora, that of 

 coral, and the fresh-water polype, scarcely differ except in magnitude ; so that 

 from having seen one, an idea of the rest may easily be formed. And Mr. W. 

 mentions this with the more freedom, as on a visit with M. Trembley in Sussex 

 at the late Duke of Richmond's, he saw the same order and economy observed in 

 the coralline, as is mentioned by M. de Peyssonnel of the coral and madrepora. 

 This phenomenon M. Trembley had discovered some time before ; and having 

 put some fresh collected coralline into a phial of sea-water, brought it to Good- 

 wood ; where after it had been suffered to remain at rest a few hours, by the 

 assistance of a microscope a great number of very small white polypes, exactly in 

 form resembling the fresh water polype, but infinitely less, were seen to protrude 

 themselves from the inequalities of the coralline, each of which served as an ha- 

 bitation for a polype. When the water was still, these animals came forth, and 

 moved their claws in search of their prey in various directions ; but on the least 

 motion of the glass, they instantly disappeared ; as was the case of the coral in- 

 sect described by our author. 



But to return. The flesh of the animal of the madrepora is so soft, that it 

 divides on the gentlest touch. This soft texture prevented M. de P. from de- 

 taching any one; and he observes that there are in those seas several large spe- 

 cies of urtica, which become pappy on the least touch. He mentions one sort 

 of above a foot in diameter, whose body is as large as a man's head, and which 

 is of a poisonous nature. After the madrepora had been preserved 3 days, the 

 contained animals covered its whole surface with a transparent jelly, which melted 

 away, and fell to the bottom of the water as the animal died ; and both the water 

 and madrepora then had a putrid fishy smell. After having destroyed and consumed 

 all the animals, the extremities of the madrepora became white. 



Imperatus seems to have bordered upon this discovery, when he says, " that 

 the extremities of the madrepora are soft, of a obscure purplish colour, contain- 

 ing a membranous substance ; whence one might suspect, that it partakes of a 

 sensitive and animal life." 



Our author made the experiment here laid down on every species of madre- 

 pora, which he found during the 3 months he continued on the coasts of Bar- 

 bary. He observed always the same appearance, allowing some little difference 

 for the colour and size of the animals, the texture of their bodies, and that of 

 the bodies themselves, on which they were produced. 



From what has been extracted, concerning the coral and madrepora, an idea may 

 be formed of the millepora, lythophyton, corallines, and sponges ; each of which is, 

 according to our author, the habitation of numerous animals, and formed by them. 

 He has given, from his own observations, particular accounts of each of these 

 productions, and divided them into genera and species witli great accuracy ; and 



VOL. X. Mm- 



