Origin of Species Variorum

→ about the vast periods which had probably elapsed before the Cambrian system, 1869

and which 1866

about the existence of living beings long before the Cambrian period, and which 1872

→ Nevertheless 1869

Notwithstanding these several facts, 1866

Nevertheless, 1872

→ beneath the Upper Cambrian formations 1869

beneath the Silurian formations 1866

OMIT 1872

→ is 1866 1869

beneath the Cambrian system is 1872

→ It does not seem probable that the 1869 1872

If these 1859 1860 1861

If the 1866

→ that their fossils have been wholly obliterated 1869 1872

obliterated 1859 1860 1861

if their fossils had been wholly obliterated 1866

→ for if this had been the case we should have found 1869 1872

we ought to find 1859 1860 1861

we ought to have found 1866

→ would always have existed 1869 1872

ought to be very generally 1859 1860 1861

ought to have existed almost always 1866

→ invariably suffered extreme 1869

suffered the extremity of 1859

always suffered the extremity of 1860 1861 1866

suffered extreme 1872

↑ 1 blocks not present in 1859 1860 1861 1866 1869; present in 1872

This same view has since been maintained by Agassiz and others.

which I wrote in 1859, →about the vast periods which had probably elapsed before the Cambrian system, are almost the same with those

used

since used

by Sir W.

Logan,

Logan.

have

....

come

proved

....

true.

....

→Nevertheless the difficulty of assigning any good

cause

reason

for the absence →beneath the Upper Cambrian formations of vast piles of strata rich in fossils →is very great. →It does not seem probable that the most ancient beds

had

have

been

wholly

generally

quite

worn away by denudation, or →that their fossils have been wholly obliterated by metamorphic action, →for if this had been the case we should have found only small remnants of the formations next succeeding them in age, and these →would always have existed in a

metamorphosed

partially metamorphosed

condition. But the descriptions which we

now

....

possess of the Silurian deposits over immense territories in Russia and in North America, do not support the view, that the older a formation is, the more

invariably it

has →invariably suffered extreme denudation and metamorphism.

The case at present must remain inexplicable; and may be truly urged as a valid argument against the views here entertained. To show that it may hereafter receive some explanation, I will give the following hypothesis. From the nature of the organic

remains,

remains

which do not appear to have inhabited profound depths, in the several formations of Europe and of the United States; and from the amount of sediment, miles in thickness, of which the formations are composed, we may infer that from first to last large islands or tracts of land, whence the sediment was derived, occurred in the neighbourhood of the

existing

now existing

continents of Europe and North America. ↑ But we do not know what was the state of things in the intervals between the

successive

several successive

formations; whether Europe and the United States during these intervals existed as dry land, or as a submarine surface near land, on which sediment