135 



Reaumer in 1727 wrote a treatise on corals, in which he 

 considered them as plants and opposed the ideas of an ob- 

 server, whose name he withheld, that they were animals. 

 This observer was Peysonnel who first studied corals on the 

 coast of Barbary, and afterwards at the island of Guadaloupe, 

 He made many very careful experiments op the coral polyps 

 in a living state, and in a paper communicated to the Royal 

 Society of London, in 1751. he fully established their animal 

 nature and showed their relation to the Actinias, which had 

 long been considered as animals. This pape^ 1 , however, was 

 never published entire. Reaumer became finally convinced 

 that he was right, but considered that the hard corals were 

 built by the polyps, as bees build their cells ; an idea which 

 still lingers in some of the popular text books. The discov- 

 eries of Peysonnel made a complete revolution in the study 

 of corals. Ellis also in 1754, proved the animal nature of 

 the hydroid polyps ; like Sertularia. From this time writers 

 on polyps became numerous. In the beginning of the pres- 

 ent century Lamark, Oken, Lamouroux and Ctivicrin their 

 works, brought something of system into the classification of 

 polyps, but still their classifications were unnatural because 

 they united all those polyps that produce hard corals into 

 one group, and those that always remain soft into another. 

 In 1828 Milne Edwards and Andouin made an elaborate study 

 of the anatomy of the polyps, and established the two natu- 

 ral orders determined by the number and structure of the 

 tentacles. The intimate relation between the Actinias and 

 coral polyps, had however been well shown by Charles A. 

 Lesueur in a paper, accompanied by excellent plates, pub- 

 lished in the Journal of the Philadelphia Academy in 1817. 



Among the numerous works published during the past 

 twenty -five years, the magnificent work of Prof. J. D. Dana, 

 of New Haven, on the Zoophytes of the U. S. Exploring Ex- 

 pedition, under Capt Wilkes, deserves particular notice. 

 This work is accompanied by a large number of excellent 

 plates of the coral polyps drawn from life. This work was 

 published in 1846. 



About this time a series of monographs of various families 

 of corals were commenced by Milne Edwards and Jules 

 Haime. These appeared at various .times, from 1845 to 

 1855, and in 1857 the work entitled Histoire Naturelle des 

 Coralliaires was published. This is a complete work on the 



