Origin of Species Variorum

→ include few 1859 1860 1861 1866

do not include many 1869 1872

→ by catastrophes; and 1859 1860 1861 1866 1869

OMIT 1872

→ lapse of actual 1859 1860 1861 1866 1869

relative, though not actual lapse of 1872

→ quite incomprehensible by us, 1859 1860 1861 1866

OMIT 1869

→ a mere fragment of time, 1859 1860 1861 1866

short, 1869

→ was created. 1859 1860 1861 1866

appeared on the stage. 1869

stages as having been of vast duration. But we shall be able to gauge with some security the duration of these intervals by a comparison of the preceding and succeeding organic forms. We must be cautious in attempting to correlate as strictly contemporaneous two formations, which →include few identical species, by the general succession of

the

their

forms of life. As species are produced and exterminated by slowly acting and still existing causes, and not by miraculous acts of

creation;

creation

and →by catastrophes; and as the most important of all causes of organic change is one which is almost independent of altered and perhaps suddenly altered physical conditions, namely, the mutual relation of organism to organism,— the improvement of one

organism

being

entailing the improvement or the extermination of others; it follows, that the amount of organic change in the fossils of consecutive formations probably serves as a fair measure of the →lapse of actual time. A number of species, however, keeping in a body might remain for a long period unchanged, whilst within

the

this

same period, several of these species, by migrating into new countries and coming into competition with foreign associates, might become modified; so that we must not overrate the accuracy of organic change as a measure of time. During early periods of the

earths

earth's

history, when the forms of life were probably fewer and simpler, the rate of change was probably slower; and at the first dawn of life, when very few forms of the simplest structure existed, the rate of change may have been slow in an extreme degree. The

~~whole~~

whole

history of the world, as at present known, although of

immense

length,

length

→quite incomprehensible by us, will hereafter be recognised as →a mere fragment of time, compared with the ages which

must have

have

elapsed since the first

organic beings,

creature,

the

progenitors

progenitor

of innumerable extinct and living descendants, →was created.