Chamberlin and Salisbury, in their recent college geology, teach that each new formation implies the destruction of an equivalent amount of older rock—­every system being entirely built up out of the older one beneath it.  Lyell and Dana teach the same thing.  If this were true, could there have been any continental growth at all?  Could a city grow by the process of pulling down the old buildings for material to build the new?  If the geology is correct, I fail to see how there would be any more land surface to-day then there was in Archaean times.  Each new formation would only have replaced the old from which it came.  The Silurian would only have made good the waste of the Cambrian, and the Devonian made good the waste of the Silurian, and so on to the top of the series, and in the end we should still have been at the foot of the stairs.  That vast interior sea that in Archaean times stretched from the rudimentary Appalachian Mountains to the rudimentary Rocky Mountains, and which is now the heart of the continent, would still have been a part of the primordial ocean.  But instead of that, this sea is filled and piled up with sedimentary rocks thousands of feet thick, that have given birth on their surfaces to thousands of square miles of as fertile soil as the earth holds.

That the original crystalline rocks played the major part in the genealogy of the subsequent stratified rocks, it would be folly to deny.  But it seems to me that chemical and cosmic processes, working through the air and the water, have contributed more than they have been credited with.

It looks as if in all cases when the soil is carried to the seabottom as sediment, and again, during the course of ages, consolidated into rocks, the rocks thus formed have exceeded in bulk the rocks that gave them birth.  Something analogous to vital growth takes place.  It seems as if the original granite centres set the world-building forces at work.  They served as nuclei around which the materials gathered.  These rocks bred other rocks, and these still others, and yet others, till the framework of the land was fairly established.  They were like the pioneer settlers who plant homes here and there in the wilderness, and then in due time all the land is peopled.

The granite is the Adam rock, and through a long line of descent the major part of all the other rocks directly or indirectly may be traced.  Thus the granite begot the Algonquin, the Algonquin begot the Cambrian, the Cambrian begot the Silurian, the Silurian begot the Devonian, and so on up through the Carboniferous, the Permian, the Mesozoic rocks, the Tertiary rocks, to the latest Quaternary deposit.