Marvels of the Untverse IOI 
Little causes beget big results, and how true this is of the corals we can see in the coral islets 
which bedeck many a wide waste of ocean. Building upon the submerged mountain-tops of the 
Pacific Ocean, they have reared through untold generations reef upon reef, until they have reached 
the surface of the water. Bank upon bank of their ancestors they have entombed, the work of 
myriads who have laboured before them, piling up cell upon cell into one vast structure of 
calcareous rock. Then dying when they reached the surface, their banks have proved the 
resting-place of flotsam and jetsam of the ocean. Seeds of trees and plants have been wafted 
across the seas; drift-wood has been cast upon its shores; seaweed, with various forms of 
littoral life in its larval stage, has been cast up on it. The coral is ground down to a fine sand, 
and birds make their appearance. Life of all kinds begins to inhabit the new island, and perhaps 
Photo by) F res: [H. J. Shepstone. 
LEAF CORALS 
Similar in the type of structure to the Mushroom Coral, the ridges are here more open and convoluted. The centra 
figure is an example of the Noble Leaf Coral. 
finally man himself comes to occupy it. And for all this the little coral-polyp is in the first 
place responsible. 
Amongst the more remarkable forms of single corals is the Mushroom Coral. The resemblance 
of this coral to the upturned top of the common mushroom is most exact. But when living, it would 
have been noticed that the diverging plates, to which we have before referred, were on the top. 
These plates look like the gills of a mushroom, but, of course, in the latter they form the under part 
of the vegetable organism. The mouth in the centre is surrounded, when living, by very short 
tentacles, and these are contracted within the ridges of the gills. In the young state the Mush- 
room Coral has a stalk, and one can often see in the older forms the hard knob where the stalk 
formerly joined it. Then finally it became severed, and fell to the bed of the sea. Sometimes the 
mushroom has become elongated, until it is twice or thrice as long as it is broad. I have a “ slug- 
coral,” as it is then called, which is nearly a foot long. 
