See page in:
1859
1860
1861
1866
1869
1872

Compare with:
1859
1860
1866
1869
1872

quicker 1861
as has been remarked by Owen, quicker 1866 1869 1872

believes that at the present day insects (as Bruce has likewise described in Abyssinia), 1861
Dr. Falconer, believes that it is chiefly insects which, 1866 1869 1872

are one chief check to 1861
in India, check 1866 1869 1872

increase. 1861
increase; and this was Bruce's conclusion with respect to the African elephant in Abyssinia. 1866 1872
increase; and this was Bruces conclusion with respect to the African elephant in Abyssinia. 1869

of different kinds, 1861
OMIT 1866 1869 1872

cause rarity, and finally extinction. So little is this subject understood, that I have heard surprise repeatedly expressed at such great monsters as the Mastodon and the more ancient Dinosaurians having become extinct; as if mere bodily strength gave victory in the battle of life. Mere size, on the contrary, would in some cases
determine,
determine
quicker extermination from the greater amount of requisite food. Before man inhabited India or Africa, some cause must have checked the continued increase of the existing elephant. A highly capable
judge,
judge
believes that at the present day insects (as Bruce has likewise described in Abyssinia), from incessantly harassing and weakening the
elephant
elephant,
are one chief check to its increase. It is certain that insects of different kinds, and blood-sucking
bats
bats,
determine the existence of the larger naturalised quadrupeds in several parts of S.
America.
America.
We see in many cases in the more recent tertiary formations, that rarity precedes extinction; and we know that this has been the progress of events with those animals which have been exterminated, either locally or wholly, through
mans
man's
agency. I may repeat what I published in 1845, namely, that to admit that species generally become rare before they become extinct— to feel no surprise at the rarity of a species, and yet to marvel greatly when
the species
it
ceases to exist, is much the same as to admit that sickness in the individual is the forerunner of death— to feel no surprise at sickness,
but,
but
when the sick man dies, to wonder and to suspect that he died by some
unknown
unknown
deed of violence.
The theory of natural selection is grounded on the belief that each new variety, and ultimately each new species, is produced and maintained by having some advantage over those with which it comes into
competition;
compe- tition;