1008 Marvels of the Universe 
remembers that a friend returning from “ India’s coral strand,” or elsewhere, has brought a lump of 
massive coral as a memento, and perhaps some interest has been felt as to the origin of the many 
objects known as corals. The forms they take are very numerous, but, in general, there are three 
or four chief types of structure: the branching corals, such as the madrepores ; the massive corals, 
which form coral reefs; the single corals, as the cup coral and the mushroom coral; and the red 
coral, which is used so much for necklaces and bracelets. There are many varieties of each of these, 
some made up of parallel pipes like the reeds of an organ, whilst others look like stags’ horns, 
or like thin, crinkled paper. The word 
“coral” is not a strictly scientific term, for 
many of the shapes formed by the work of 
the coral-polyps, or, as they have been 
called, the coral-anemones, are not made of 
hard limestone, such as is the case with 
those mentioned, but are made up of horny 
material, such as in the case of the sea- 
fans, which we have already dealt with in 
MARVELS OF THE UNIVERSE. We are more 
particularly concerned now with the hard, 
stony corals, and some of these are shown 
in our illustrations. All of these are made 
up of carbonate of lime. 
It must be remembered that in looking 
at these beautiful objects we only see the 
marvellous skeleton which the polyps have 
formed. We human beings have the power 
of taking from the food we eat the limy 
material which is used to form our internal 
skeletons. It is quite an involuntary action 
on our part. We form our skeletons with- 
out knowing it. The lowly-organized polyp 
extracts just the same limy material from 
the sea, and perhaps from its food, and 
makes its skeleton. These skeletons are the 
“corals”? which we handle. The polyps 
have gone. The thin rind of flesh in which 
they were seated has dried up, or has been 
Photo by) [S. L. Bastin. 
INTBILILIGENT ROOTS. decomposed, and nothing remains of the 
A Beech whose trunk was hollowed by decay sent down new hundreds of wonderful creatures whose work 
roots into the cavity on their way to the earth. survives them for so long. 
Nothing is more remarkable than the fact that the coral-polyps form colonies containing 
thousands of individuals, all of which are joined together into one united kingdom of corals. The 
jelly-like flesh which surrounds the hard part is perforated by canals through which circulates what 
corresponds to the blood of higher animals. Seated in clefts in this flesh, the polyps are just where 
these canals open out on to the surface, and there these radiant flowers of the sea expand their 
petals in the shape of tentacles. That they are not flowers, of course every one knows ; but to an 
observer seated in a flat-bottomed boat whose bottom is not wood but plate-glass, a coral reef 
is a perfect garden of lovely tints, whilst amongst the coloured polyps themselves there dart here 
and there those brilliantly-painted fish, which have taken upon themselves the very colours of the 
coral bank. ‘‘ Zoophytes,” or animal-plants, was the name given to many of these lowly creatures 
