Page:The aquarium - an unveiling of the wonders of the deep sea.djvu/163

122 conical stone, the whole being nine or ten inches in height. The basal stone is densely covered with parasitic Zoophytes, and tubicolous Annelides of many species.

But our admiration of this handsome Coral is much heightened when we know something of its nature. We see that its walls, which are not more than one thirtieth of an inch in thickness, are composed of stony substance, yet very brittle. Closer examination shows that this thickness, small as it is, includes two ranges of cells, which are placed back to back, opening by oval orifices on both sides of the walls.

Every cell is inhabited (or rather has been, for the older ones are dead and vacant before the younger are formed) by an active Polype of the Bryozoan Class, whose head, crowned with a funnel of radiating ciliated tentacles, protrudes from the orifice or is withdrawn into it at pleasure. These all are united by a common life; a common bond of sensation and of nutrition connects the whole of the individuals into one compound being. A single Polype, inhabiting a solitary cell, began the colony, which has grown by the continual formation of new individuals on every side, as buds grow into branches, which bud again and form a tree.

Some idea of the populousness of such a community may be gathered from the following calculations. I took a piece from my specimen, on which I carefully marked out an area of one eighth of an inch square. Within this I found the orifices of 45 cells; as the rows are double, this would give 90 cells in every