6 CURIOUS HOMES AND THEIR TENANTS. 



last animal is the same one that burst to pieces it 

 would indeed be hard to say. 



Sometimes, however, these curious little creatures 

 build themselves habitations as light, fragile, and 

 delicate as frost crystals. The species that do this 

 live in sea water. Many of their homes are shaped 

 like flasks ; some appear, when magnified, like the gem 

 fruits that Aladdin found in the magic caverns ; some 

 look like tiny jewel beads, others grow in elegant 

 spirals — in short, the variety of their forms and dec- 

 orated surfaces seems inexhaustible. Thousands of 

 living and fossil species have been distinguished by 

 naturalists. ISTothing relating to these bits of living 

 jelly is quite so wonderful or important as the part 

 they take in building up the earth. 



Once upon a time, as old stories begin — though 

 just how long ago no one can tell, for, if we are to be- 

 lieve geologists, countless centuries have passed since 

 the vast ancient oceans contained a large per cent of 

 lime and also unnumbered populations of shell-bear- 

 ing amoebae — all of these minute animals were for 

 ages and ages constantly employed in building their 

 pretty little dwellings from the lime they took from 

 the water in which they lived. Billions of billions, 

 vast numbers, too great for human conception, of 

 generations followed each other in brief succession, 

 their corruptible parts disappeared, and their shells 

 falling in a never-ending shower upon the bot- 

 tom of the ocean, in its shallower parts, built the 

 islands and continents of a primitive world, in what 

 geologists call the Cretaceous or Chalk period. It is 



