GENERAL STRUCTURE OF ZOOPHYTES. 15 



through the whole zoophyte, although extending to a breadth of four 

 feet. 



9. Secretion of the Corallum.* Coral secretions take place either 

 from the interior tissues of the polyps, or from the foot or base, and in 

 a few species only, in the exterior cuticle. The corallum in the live 

 zoophyte is therefore in general wholly concealed within the polyps, 

 and is in no part external. 



No peculiarities of structure, external or internal, have been ob- 

 served distinguishing the coral-secreting polyps from those which do 

 not secrete coral. Animals of both kinds belong to the same family, 

 and hence this peculiarity affords at the highest only a generic dis- 

 tinctionf {h 109). 



* 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 deriva- 

 tions and use are discussed at length by Theophrastus in his work on plants, Book iv. 

 KoupaXiou is the ancient Greek form, as says Dionysius, " iravTrj yap Xi^os spv spu^pou xou- 

 paXioio." — The more recent Greeks, among whom are Dioscorides and Hesychius, wrote 

 the word xopaXXiov. Among the Latins, Ovid says, " Sic et Curalium, quo primum con- 

 tigit auras tempore durescit." Avienus uses Corallum: " Fulvo tamen invenire Corallo, 

 quasrere vivendi commercica." Among the derivations suggested, that of xop)], damsel, 

 and aXj, sea, appears the most probable. 



The word Corallium has been in most general use ; but as it is now the name of a 

 particular genus, it has of late been rejected for poltjpifer, polypary, and pohjpidom, 

 sigmCy'mg polyp-bearer, or a hive or house of polyps. These terms are all objectionable, 

 for the reason that the polyps contain the coral, instead of the coral containing the 

 polyps. On this ground neither of them has been adopted here, but instead the old word 

 Corallum,, which is sufficiently distinct from the name of the genus Corallium. 



We have then the term Zoophyte for the whole polyp mass, whether simple or com- 

 pound, coral-making or not ; the term polyp for the individual animals ; and Corallum for 

 the framework or skeleton secreted by polyps. To express the fact that certain polyps 

 secrete a corallum, we use the expression coral-forming or coralligenous. The animals 

 of a coral zoophyte are coral-animals or coral-polyps. 



f The definition of Zoophytes excludes the Flustroid tribe of polyps, called Bryozoa 

 by Ehrenberg." The peculiarities of these animals were first pointed out by Milne 

 Edwards and Audouin,*" who showed that in place of the simple digestive sac of the Ser- 

 tularidcB, to which they had been thought allied, they have a regular stomach, and an 

 intestine which curves upon itself and terminates in the disk ; and besides, their arms or 



^ Berlin Trans., 1832. — The name Bryozoa is derived from fifuoi, moss, and ifoicv, animal. The oilier 

 zoophytes Elirenberg calls Anthozoa, meaning Jlower-animal, — excepting the Sertularidce and the allied 

 species, which he subsequently named Dimorph(Ea. 



^ Annales des Sei. Nat. xv. 1898. — Edwards and Audouin here point out the relations of these ani- 

 mals to the AscidisE. 



