1014 Marvels of the Universe 
I oto By] [H. J. Shepstone. 
MUSHROOM CORAL. 
In this photo the polyps are alive and active. It will be seen that they effectually hide the stony base of the Coral and look 
like large Anemones. The upper figure with the polyps partially retracted gives better indication that it is a Coral. 
what mother-of-pearl is, and it seems probable that the ‘‘ Madrepore” coral was really called so 
because it was the “ mother-stone.” But it soon came to be noticed that different corals had 
different forms and arrangements of the little holes, or cups, in which the polyps lived. So the 
Greek word which meant ‘“‘ stone” came to be confused with a similar word, which meant a “little 
hole,” which differed from the other in one letter only. So we had millepora, or thousand-pore ; 
heliopora, or sun-pore ; pocillopora, or little-cup pore, and others. 
We have already referred to the wonderful Barrier Reef off the north-eastern Australian coast. 
This is a coral reef on a colossal scale. The very mention of it brings to mind Saville Kent’s monu- 
mental book, and one of his photographs of a portion of the reef is shown in illustration of this 
article. The great reef extends for over twelve hundred miles, at a distance from the shore of 
twenty or thirty miles, or even more. Here, in the greatest profusion and variety, are found all the 
chief forms of corals, and, indeed, our knowledge of them has been inconceivably increased since 
the Barrier Reef has been so thoroughly explored. More recently coral-reef exploration of another 
kind has taken place, in order to prove the truth or otherwise of Darwin’s famous theory of coral- 
islands. At Funafuti, one of the Ellice Islands, several borings have been made, one of which pene- 
trated to a depth of no less than one thousand one hundred and fourteen feet. The result of the close 
examination of the cores of coral brought up was to re-establish the truth of Darwin’s theory. The 
island of Funafuti was shown to have been gradually formed during the subsidence of the founda- 
tions on which it rests, and this subsidence amounted to at least eight hundred and seventy-seven 
feet. Nothing but coral-reef rock was met with throughout the whole of the boring. It would be 
interesting to know exactly the rate at which various corals grow, but with the exception of one 
or two records, we have little information on the subject. Agassiz, from his observations on the 
