264 PHILOSOPHICAL TRANSACTIONS. [aNNO 1751. 



are, and how they are formeci. He proceeds to remark that divers productions 

 are found in the sea of a stony nature. These bodies are always equal, and al- 

 ways the same in their different species : they have the same arrangement of 

 parts, the same essential figure ; and differ in nothing but their outward form, 

 like different vegetables. They are all pierced with holes and pores, which are 

 of the same size and figure, and are of the same disposition in each species ; so 

 that it appears evident that they are all produced from the same matter. But 

 how they are produced, and their mechanism, has been hitherto unknown. 



When treating of coral, our author has given several observations of other 

 persons relating to it ; but he finds none relating to the madrepora, and the 

 other sea productions. But the knowledge which he had acquired on the nature 

 of coral, conducted him to the discovery, which he made, of the animals that 

 form the madrepora. 



As this system is new, he thinks it necessary to give hi§ observations, as they 

 enabled him to form it. He defines the madrepora* to be all those marine bodies 

 which are of a stony substance, without either bark or crust, and which have 

 but one apparent opening at each extremity, furnished with rays proceeding from 

 the centre to the circumference. He then takes notice of the means by which 

 he found the madrepora to be the habitation of animals. So early as the year 

 1719, when his curiosity carried him to the coral fishing on the coast of Pro 

 vence ; and though intent only upon coral, and neglecting to examine any other 

 marine production, he nevertheless observed that the extremities of the madre- 

 pora were soft, and covered with a mucosity, which had a fishy smell. Thence 

 he suspected that they contained some kind of animal ; but his curiosity stopped 

 here. Afterwards, being on the coasts of Barbary, the fishermen brought him, 

 in a barrel of sea-water, one of those madreporas which are called in Provence, 

 fenouille de mer, or sea-fennel. It had been put into the barrel as soon as it 

 was taken out of the sea ; and he observed, that the extremities of this madre- 

 pora were soft and tender, furnished with a transparent mucosity, like that of 

 snails ; these extremities were of a beautiful yellow colour, and were 5 or 6 lines 

 in diameter. In this he saw an animal, resembling the cuttle-fish, polype, or 

 sea-nettle. The body of this fish filled the centre ; its head was placed in the 

 middle of it, and was surrounded by several feet or claws : these feet filled the 

 intervals of the partitions observed in the madrepora, and were at j)]easure 

 brought to its head, and were furnished with yellow paj)illae. Its head or centre 

 was lifted up occasionally above the surface, and often contracted and dilated itself 

 like the pupil of the eye. He had the pleasure of seeing it move distinctly all its 

 claws, as well as its head or centre. We can easily conceive all these motions, 

 from what we have lately seen in the fresh-water polype, discovered by M. Trem- 

 bley : and it is to be observed that the great sea polype (which is found on our 



