62 CLASS II. 
In the two following years BERNARD DE JUSSIEU, the celebrated 
Botanist, investigated Alcyoniwm (Lobularia), Flustra and Tubu- 
laria on the coast of Normandy, and confirmed PEYSONNEL’S dis- 
covery: whilst REAuMUR also adopted his views. LiInnaus, 
accordingly, transferred the Corals and stone-plants to the animal 
kingdom: and thus more than half a century was required to 
effect the adoption by Science, as a firm truth, of that view which 
FerrANTE Imperato had announced at the beginning of the 
16th century!. Exwis, PALLAs, CAvoLini and other authors, 
in the latter half of the past century, extended and multiplied our 
acquaintance with these interesting marine animals, of which the 
investigation still affords to scavants of the present day a rich 
material for new and important discoveries. 
Polyps are either naked, or are provided with a body more or 
less hard, which they surround like a bark, or by which they are 
surrounded. ‘T’o the naked Polyps belong the well-known Armed 
Polyp of fresh-water (Hydra L., Polype d'eau douce, & bras en forme de 
cornes). The body of this animal is hollow within, and terminates 
in a little cylindrical stalk that is without any opening. There is 
a single row of tentacles round the mouth which can be extended 
like long rays, or be contracted into little conical swellings. 
These tentacles are not all formed at once, but at different times: 
their number is therefore indeterminate, and frequently varies in the 
same species. Generally there are not more than six tentacles 
present: rarely more than twelve. By their assistance the fresh- 
water Polyp can creep along upon water-plants or upon the bottom, 
overpower its prey, and convey it to the mouth. These Polyps are 
very voracious, and feed upon minute Crustaceans (Oypris, Daphnia, 
Monoculus, &e.), and upon worms (Stylaria paludosa Lam. Nais, 
Tubifex, &c.), which frequently surpass them in bulk. Accordingly 
1 To complete this compressed historical review, we refer to B. DE Jusstzu, Hxamen 
de quelques productions marines, &c. Mém. de ?Acad. royale des Sciences, 1742. pp. 290 
—302; R&eaumuR, Mémoires pour servir a Histoire des Insectes, Tom. Vi. 1742. Pre- 
face, pp. 49—80 ; Pauuas, Elench. Zoophytor. pp. 13—20; LAMOIGNON MALESHERBES, 
Observations sur V Histoire natur. de BUFFON et de DAUBENTON. Paris, 1798, I. pp. 154 
—206 ; EHRENBERG, Die Corallenthiere des rothen Meeres, pp. 4, 5; Minne Epwarps, 
Ann. des Sc. Natur. sec. Série, Tom. vi. Zoologie, 1836. pp. 5—9; FLourEns, Analyse 
dun ouwrage manuserit intitulé, Traité du Corail &e. par Dk PEYSONNEL, Ann. des Se. 
Nat. sec. Sér. Tom. 1x. Zoologie, 1838, pp. 334—351. 
