140 GEOLOGY. 
The Contents of the Rocks, 
The contents of the rocks receive the general name of fossils, from the 
Latin fossus, dug, because they require generally to be dug out of the 
earth. Fossils may be divided into two great classes, animals and plants. 
Fossil Animals.—In the rocks, we discover specimens of every class 
included in the animal kingdom. We find corals of all kinds, and of the 
most beautiful structure, some branched like some of the corals of the 
present seas, others standing in masses on the very spots where they lived 
and died, their remains giving beauty to our finest marbles. We see 
star-like creatures of all kinds, either spreading abroad their arms or curled 
up at rest, as they may be seen any day during the ebb of tide. Shells 
of every form, size, and colour meet us at every step, as distinct as we 
now find them on the shore ; and some formations, of vast thickness and 
extent, are formed entirely of the habitations of these little creatures. We 
may also gather crustaceans, such as the crab and the lobster, the minutest 
parts of their structure being perfectly preserved. We discover fishes 
of every kind and size, sometimes entire, as they fell to the bottom at 
death, or crushed and broken in the convulsions to which the rocks have 
been subjected. We can gather the hard scales, that defended them like 
armour; can form collections of their teeth, their fins, their jaws, and 
their eggs; and can construct them again as they swam about in the ancient 
seas. Insects, too, we can gather of every kind, and can see them as they 
flew about in the old forests and got entangled in the resin of the great 
old trees. Birds, too, are found, though not so plentifully as other 
— creatures, as, from their manner of life, they were not so easily carried 
' down by rivers, and deposited in the mud at their mouths. We find 
reptiles of immense size, crocodiles, and lizards, and flying dragons, with 
their terrible teeth, sweeping tails, and adamantine hides. We come upon 
beasts of every size, from little creatures that burrow in the ground, to 
gigantic deer, elephants, rhinoceroses, and mammoths ; and may enter the 
very dens in which lived beasts of prey, and to which they bore their 
captured victims. 
These creatures differ more or less from those that now inhabit the 
globe, but they are members of the same classes ; and catalogues of them 
have been formed as of those of the present day. A visit to a museum 
in which fossils are exhibited would astonish you with the multitude, 
variety, and beauty of those fossil creatures, and especially with the won- 
derful preservation of organisms the most delicate and frail. 
Fossil Plants.—But the vegetable kingdom is as fully represented in 
the rocks as the animal. We find trees of the most varied kinds, with 
their roots, stems, branches, leaves, flowers, and fruit. We can look 

we Pt. 
ens 
