In the case of the Colorado, Zittel says that:

"Powell's explanation of the apparent enigma is that after the river had eroded its channel rocks were uplifted in one portion of its course, but so slow was the rate of uplift that the river was enabled to deepen its channel, either proportionately or more rapidly, so that it was never diverted from its former course."

It was by similarly cunning inventions that the early writers on astronomy, alchemy, and medicine evaded the force of accumulated facts which told against their absurd theories.

We have now completed our survey of the strictly stratigraphical phases of this question, and have found four very remarkable principles about the rocks, which I wish to summarize here before proceeding further.

(1) The "broad fact," as stated by Zittel and Dana, that any kind of rocks whatever, i.e. containing any kinds of fossils, even the "youngest," may rest on the Archaean, and may thus in position, as also in texture and appearance, resemble the very oldest deposits on the globe.

(2) That any kind of beds may rest in such perfect conformability on any other so-called "older" beds over vast stretches of country that, "were it not for fossil evidence, one would naturally suppose that a single formation was being dealt with," while "the vast interval of time intervening is unrepresented either by deposition or erosion." The youngest seem to have followed the oldest in quick succession.

(3) That in very many cases and over many square miles of country these conditions are exactly reversed, and such very "ancient" rocks as Cambrian limestones are on top of the comparatively "young" Cretaceous, while the lime between them "acts exactly like the line of contact of two nearly horizontal formations," and in a natural section made by a river the two "appear to succeed one another conformably." To any one ignorant of the theory of life succession they have every appearance of having been deposited as we find them.

(4) That the rivers of the world, in cutting across the country, completely ignore the varying ages of the rocks in the different parts of their courses, and act precisely as if they began sawing at them all at the same time.

Now I know not what additional fact can be demanded or imagined to complete the demonstration that there is no particular order in which the fossils can be said to occur as regards succession in time. It is true, some fossiliferous deposits, metamorphosed almost beyond recognition, and buried deep beneath thousands of feet of subsequent deposits, have enough appearance of remote antiquity about them in all conscience. But to increase this antiquity by saying that other equally prodigious masses of rocks elsewhere were deposited long after these, or by pointing to still other deposits in another region which are said to be older than any of the others, is an illogical and wholly unscientific procedure. I fear I could scarcely confine myself within the bounds of parliamentary language were I to attempt to express an opinion regarding any effort that may now be made to justify the life succession theory in view of the above acknowledged facts.