158 Mr. J. D. Dana on Zoophytes. 



the most distinguished names in science are committed on oppo- 

 site sides. If animals, they have only the most general properties 

 of animal life, and are less nearly related to polyps than to the 

 infusorial animalcules. They are arranged with the latter by 

 Dujardin. 



Though zoophytes have no connection with the vegetable 

 kingdom, polyps may be styled with much propriety flower- 

 animals. The word zoophyte*, originally used by Linnseus, 

 alluded to their supposed intermediate nature. Still, the name is 

 sufficiently appropriate, although the idea in which it originated 

 is exploded. They are plants in form even to the coral-polyps 

 which blossom over the surface ; yet in the mode of receiving, 

 digesting and assimilating nutriment, and every other function 

 of life, they are animal. 



The relation of the coral to the coral animal, and the mode of 

 its formation, are subjects about which much error has been pub- 

 lished ; and although now correctly explained in some scientific 

 treatises, very erroneous impressions largely prevail. Without 

 entering into particulars in this place, one single fact should be 

 here stated and duly considered ; it is this : — coral is not the 

 residence or hive of polyps ; on the contrary, it is contained 

 within the polyps, instead of containing them. It is formed 

 within them by animal secretion, as bones are formed within 

 other animals; and in most living zoophytes it is wholly in- 

 closed, showing not a spine or point externally. This is the case 

 with the Madrepore ; no part of the coral is seen externally while 

 the animal is alive in the water. The idea that coral polyps re- 

 treat into cells is therefore wholly without foundation. Some- 

 times the summit or flower-shaped part of the polyp becomes 

 concealed, in a manner a little similar to the withdrawal of a tur- 

 tle's head ; but even this semblance of retreat is by no means 

 general among the ordinary coral zoophytes. 



There is no mechanical accumulation of material by the polyp : 

 they are as unconscious of the coral secretions going on within 



* The word zoophyte is from the Greek £a>ov, animal, and <fiva>, to grow 

 like a plant. Blainville states that the term was introduced by Sextus Em- 

 piricus and Isidore de Seville in the sixth century. It has been differently 

 restricted in its use by authors, and, on account of its various applications, 

 is wholly rejected by Lamarck. Other late scientific writers retain it, and 

 it is also the popular designation. 



Ehrenberg has proposed to substitute Phytozoa, derived from the same 

 roots. But science requires a name that will apply to the whole compound 

 structure — the coral tree, sea-fan, or mass of whatever shape ; and phyto- 

 zoon refers only to a single polyp, or phytozoa to polyps in general. These 

 cannot supply the place of the very convenient term3 zoophyte and zoo- 

 phytes. Moreover, the term phytozoa or phytozoaires (plant-animals) has 

 been applied to the minute monad-like cellules found in the tissues of some 

 plants, and supposed to be animalcules or plant-entozoa. 



