Mr. J. D. Dana on Zoophytes. 159 



them, and as free from actual labour and industry, as we are in 

 the construction of our bones. 



The existence of such terms in the science as polypary, poly- 

 pidom, applied to coral, signifying a hive or house of polyps, indi- 

 cates the errors of former days ; errors which science should not 

 perpetuate. As a substitute, the old term Corallum* is conve- 

 nient and unobjectionable. Corallium has been rejected because 

 of its application to a particular genus of corals. In Corallum, 

 we have a familiar word, and one which implies no hypothesis 

 or erroneous comparison. The analogy between the work of the 

 polyp and that of the bee or ant, though often suggested, is wholly 

 without foundation. 



The existence of coral secretions is by no means essential to 

 the existence of polyps. Although a large number of species 

 form coral, there are also many that are wholly fleshy, or secrete 

 only a few scattered granules of lime. The Actinia or sea-ane- 

 mones, as they are familiarly called, are examples of these fleshy 

 species. In every point of structure, and in every function, ex- 

 cept that of coral-secreting, they are identical with coral animals. 

 They have also the same resemblance to flowers when expanded, 

 and their rich tints and large size make them the most brilliant 

 flower- animals of any seas. 



One of the most singular characters of zoophytes is their fre- 

 quent compound nature. The branching Madrepore is an ex- 

 ample of this compound structure. There are hundreds of polyps 

 united in a single individual ; each little prominence containing 

 a cell pertained to a separate animal; and by counting these 

 prominences over a branch of coral, the number of flower- animals 

 combined in its production may be ascertained. In the same 

 manner, in Astrseas, each radiate cell or depression over the sur- 

 face marks the site of a polyp. The many animals, though di- 

 stinct in some functions, are still mutually dependent in others, as 

 we shall explain in the sequel. 



Although these compound forms are most common, yet there 

 are other zoophytes which are always simple polyps. The coral 

 in such cases is a single isolated cup or radiated disc, and the 

 coral animal is a solitary flower. These simple polyp-flowers 



* Coral has been variously designated in both ancient and modern times. 

 The terms Corallium, Corallum and Curalium were all used by the ancients, 

 and their derivations and use are discussed at length by Theophrastus in his 

 work on plants, book iv. Kovpakiov is the ancient Greek form, as says 

 Dionysius, Trdvrr] yap Xtdos i&lfo epvdpov KovpaXioio. The more recent 

 Greeks, among whom are Dioscorides and Hesychius, wrote the word ko- 

 pdWiov. Among the Latins, Ovid wrote, " Sic et curalium quo primum 

 contigit auras tempore durescit." Avienususes Corallum. Among the de- 

 rivations suggested, that of tcoprj, damsel, and aKs, sea, appears the most 

 probable. 



