AMERICA THE OLD WORLD. 25 
lived and died in its waters or along its banks, 
when every lake and pond deposited at its bot- 
tom in successive layers the lighter or heavier 
materials floating in its waters and settling grad- 
ually beneath them, the process by which strati- 
fied materials are collected and gradually harden 
into rock is more easily understood. But when 
the solid surface of the earth was only just begin- 
ning to form, it would seem that the floating 
matter in the sea can hardly have been in suf- 
ficient quantity to form any extensive deposits. 
No doubt there was some abrasion even of that 
first crust ; but the more abundant source of the 
earliest stratification is to be found in the sub- 
marine volcanoes that poured their liquid streams 
into the first ocean. At what rate these materi- 
als would be distributed and precipitated in reg- 
ular strata it is impossible to determine ; but that 
volcanic materials were so deposited in layers is 
evident from the relative position of the earliest 
rocks. I have already spoken of the innumer- 
able chimneys perforating the Azoic beds, narrow 
outlets of Plutonic rock, protruding through the 
earliest strata. Not only are such funnels filled 
with the crystalline mass of granite that flowed 
through them in a liquid state, but it has often 
poured over their sides, mingling with the strati- 
fied beds around. In the present state of our 
knowledge, we can explain such appearances only 
2 
