98 THE BEAUTIES OF NATURE CHAP, 
ish Columbia, and turned them into a suc- 
cession of pools or marshes, but this is a 
slight matter compared with the action of 
earthworms and insects’ in the creation of 
vegetable soil; of the accumulation of ant- 
malcules in filling up harbours and lakes; 
or of Zoophytes in the construction of coral 
islands. 
Microscopic animals make up in number 
what they lack in size. Paris is built of 
Infusoria. The Peninsula of Florida, 78,000 
square miles in extent, is entirely composed of 
coral débris and fragments of shells. Chalk 
consists mainly of Foraminifera and fragments - 
of shells deposited in a deep sea. The num- 
ber of shells required to make up a cubic inch 
is almost incredible. Ehrenberg has estimated 
that of the Bilin polishing slate which caps 
the mountain, and has a thickness of forty 
feet, a cubic inch contains many hundred 
million shells of Infusoria. 
In another respect these microscopic organ- 
1 Prof. Drummond (Tropical Africa) dwells with great force 
on the manner in which the soil of Central Africa is worked up 
by the White Ants. 
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