VOL. XLVII.] PHILOSOPHICAL TRANSACTIONS. 26l- 



pieces of coral growing upon detached pieces of rock, glass bottles, broken pots, 

 and other substances, .from which the plant could receive no nourishment. It 

 has been said by great authority, that coral grows from the rocks perpendicularly 

 downwards ; but our author has seen some growing to a round flint, which must 

 necessarily have vegetated upwards, like most other plants. 



M. de Peyssonncl proceeds to examine, whether coral is a plant, according to 

 the general opinion, or a petritication or congelation, according to some ; and 

 after exhibiting the various arguments delivered in support of these, he concludes, 

 that coral, as well as all other stony sea-plants, and even sponges, are the work 

 of difterent insects, particular to each species of these marine bodies, which la- 

 bour uniformly according to their nature, and as the Supreme Being has ordered 

 and determined. The coral-insect, [worm.] which is here called a little urtica, pur- 

 pura, or polype, and which Marsigli took for its flower, expands itself in water, and 

 contracts itself in air, or when you touch it in water with your hand, or pour 

 acid liquors to it. This is usual to fishes or insects of the vermicular kind. 



When our author was upon the coasts of Barbary in 1 725, he had the pleasure 

 of seeing the coral-insect move its claws or legs ; and having placed a vessel of. 

 sea- water with coral therein near the fire, these little insects expanded them 

 selves. He increased the fire, and made the water boil, and by these means 

 kept them in their expanded state out of the coral, as happens in boiling shell- 

 animals, whether of land or sea. Repeating his obser\'ations on other branches, 

 he clearly saw that the little holes perceptible on the bark of the coral, were the 

 openings through which these insects went forth. These holes correspond with 

 those little cavities or cells, which are partly in the bark, and partly on the sub- 

 stance of the coral ; and these cavities are the niches which the insects inhabit. 

 In the tubes, which he had perceived, are contained the organs of the animal; the 

 glandules are the extremities of its feet, and the whole contains the liquor or milk 

 of coral, which is the blood and juices of the animal. When he pressed this little 

 elevation with his nails, the intestines andwholebcxly of the insect came out mixed 

 together, and resembled the thick juice furnished by the sebaceous glands of the 

 skin. He saw that the animal, when it wanted to come forth from its niche, 

 forced the sphincter at its entrance, and gave it an appearance like a star with 

 white, yellow, or red rays. When the insect comes out of its hole without ex- 

 panding itself, the feet and body of it form the white appearance, observed by 

 Marsigli ; but being come forth, and expanded, it forms what that gentleman 

 and our author took for the petals of the flowers of coral, the calyx of this sup- 

 posed flower being the body of the animal protruded from its cell. The milk 

 before mentioned is the blood and natural juice of the insect, and is more or less 

 abundant in proportion to its health and vigour. When these insects are dead, 

 they corrupt, and communicate to the water the smell of putrid fish. 



