THE LOWER FOEMS OF LIFE. 117 



surface blooms with Coral polyps in place of leaves and flowers. 

 Shruberries, tufts of rushes, beds of pinks, and feathery mosses are 

 most exactly imitated. Many species spread out in broad leaves or 

 folia, and resemble some large-leaved plant just unfolding ; when alive 

 the surface of each leaf is covered with polyp flowers. The cactus, 

 the lichen clinging to the rock, and the fungus in all its varieties 

 have their numerous representatives. Besides these forms imitating 

 vegetation, there are gracefully-modelled vases, some of which are 

 three or four feet in diameter, whose symmetrical surface is gor- 

 geously decked with polyp stars of purple and emerald green. All the 

 many shapes proceed in each instance from a single germ, which 

 grows and buds under a few simple* laws of development, and thus 

 gives origin either to the branch, the broad leaf, the column, or the 

 hemisphere." 



CHAPTER VIII. 



COBAL (continued). 



THE passage from the Zoophytes or Corallines to the true Corals is 

 illustrated by the Alcyonaria, which, it will be remembered, are 

 polyps with eight tentacles or multiples of that number. 



In the frontispiece (Fig. 170) is a drawing of the Alcyonium 

 poculum, or Neptune's cup, which is sometimes, as may be seen in 

 the British Museum, built up to a large size. These cups are the 

 skeletons of the polyps, which are seen covering the surface inside 

 and out with their crenosarc or connecting sarcode. They are found 

 in shallow water in tropical climates, and were first discovered by 

 Sir Stamford Raffles upon the coral reefs which surround the 

 island of Sumatra. The texture of these " cups " is spongy in 

 appearance and to the touch, but they contain within it numerous 

 flinty crystalline deposits, which give firmness and solidity to the 

 structure. These "cups" are sometimes o'f considerable size, as 

 much as three or four feet high, and two feet broad. Let us next 

 examine the " Sea-Fan " (Fig. 153, frontispiece). Observe that in 

 this (as in all but one of the other figures) I have left a part of the 

 skeleton covered over with the living polyps and their coenosarc, and 

 I have in this instance drawn one of the polyps relatively larger to 

 show its general form. Now, these creatures secrete and fashion, 

 by their vital force, this beautiful arborescent horny network, which 

 is to serve as the skeleton of the colony. Also remark that the 

 polyps, as seen in the figure, although to a certain extent enjoying a 



