Origin of Species Variorum

→ Not very long ago M. Barrande 1872

M. Barrande has lately 1859 1860 1861

M. Barrande not long ago 1866

Not long ago M. Barrande 1869

→ OMIT 1869 1872

to the Silurian system, 1859 1860 1861 1866

→ species, beneath the then known Silurian system; and now, still lower down in the Lower Cambrian formation, Mr. Hicks has found in South Wales beds rich in trilobites, and containing various molluscs and annelids. 1872

species. 1859 1860 1861 1866

species beneath the old Silurian system. 1869

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

Traces of life have been detected in the Longmynd beds beneath Barrande's so-called primordial zone.

→ periods; and the existence of the Eozoon in the Laurentian formation of Canada is generally admitted. 1872

periods. 1869

→ as a comparatively 1869 1872

comparatively 1866

→ is highly organised for its class; 1872

for its class is highly organised; 1866 1869

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

and which 1866

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

→ Nevertheless, 1872

Notwithstanding these several facts, 1866

Nevertheless 1869

→ OMIT 1872

beneath the Silurian formations 1866

beneath the Upper Cambrian formations 1869

→ beneath the Cambrian system is 1872

is 1866 1869

→ 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

→ suffered extreme 1872

suffered the extremity of 1859

always suffered the extremity of 1860 1861 1866

invariably suffered extreme 1869

lowest Silurian stratum the

dawn

life

this

planet.

Other highly competent judges, as Lyell and

the late

....

E. Forbes ,

dispute

disputed

have disputed

this conclusion. We should not forget that only a small portion of the world is known with accuracy. →Not very long ago M. Barrande added another and lower

stage

stage,

→OMIT abounding with new and peculiar →species, beneath the then known Silurian system; and now, still lower down in the Lower Cambrian formation, Mr. Hicks has found in South Wales beds rich in trilobites, and containing various molluscs and annelids. ↑ The presence

also

....

of phosphatic nodules and bituminous

matter

matter,

even in

some of the lowest azoic rocks, probably indicates life at these →periods; and the existence of the Eozoon in the Laurentian formation of Canada is generally admitted. There are three great series of strata beneath the Silurian system in Canada, in the lowest of which the Eozoon

was

found;

found.

and

....

Sir W. Logan states that their

united

"united

thickness may possibly far surpass that of all the succeeding rocks, from the base of the palæozoic series to the present time. We are thus carried back to a period so

far

....

remote, that the appearance of the so-called Primordial fauna (of Barrande) may by some be considered

....

→as a comparatively modern event." The Eozoon belongs to the most lowly organised of all classes of animals, but →is highly organised for its class; it existed in countless numbers, and, as Dr. Dawson has remarked, certainly preyed on other minute organic beings, which must have lived in great numbers. Thus the

words

words,

above given,

....

which I wrote in 1859, →about the existence of living beings long before the Cambrian period, and which are almost the same with those

used

since used

by Sir W.

Logan.

Logan,

~~have~~

have

come

~~proved~~

proved

~~true.~~

true.

→Nevertheless, the difficulty of assigning any good

cause

reason

for the absence →OMIT of vast piles of strata rich in fossils →beneath the Cambrian system 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 →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