Origin of Species Variorum

→ parent, if this view be correct, 1859 1860 1861 1866

parent-form, 1869 1872

→ long-continued 1859 1860 1861 1866

a long course of 1869 1872

→ here enjoy good 1859 1860 1861 1866

are here perfectly 1869 1872

→ be generally 1859 1860 1861 1866 1869

is in most cases 1872

→ in the case of 1859 1860 1861 1866 1869

with 1872

→ or becoming 1859 1860 1861 1866

that is, they become 1869 1872

→ trees 1859 1860 1861 1866

the same species 1869 1872

→ of the same species growing 1866

growing 1859 1860 1861 1869 1872

→ in this country to possess 1859 1860 1861 1866 1869

to possess in this country 1872

→ England; and I could give other cases. 1866 1869 1872

England. 1859 1860 1861

→ within historical times having largely extended 1859 1860 1861 1866 1869

having largely extended, within historical times, 1872

all the species of the same genus

are

have

descended from a single →parent, if this view be correct, acclimatisation must be readily effected during →long-continued descent. It is notorious that each species is adapted to the climate of its own home: species from an arctic or even from a temperate region cannot endure a tropical climate, or conversely. So again, many succulent plants cannot endure a damp climate. But the degree of adaptation of species to the climates under which they live is often overrated. We may infer this from our frequent inability to predict whether or not an imported plant will endure our climate, and from the number of plants and animals brought from

different

warmer

countries which →here enjoy good

healthy.

health.

We have reason to believe that species in a state of nature are

limited

closely limited

in their ranges by the competition of other organic beings quite as much as, or more than, by adaptation to particular climates. But whether or not

this

the

adaptation →be generally very close, we have

evidence

evidence,

→in the case of some few plants, of their becoming, to a certain extent, naturally habituated to different

temperatures;

temperatures,

→or becoming

acclimatised;

acclimatised:

thus the pines and rhododendrons, raised from seed collected by Dr. Hooker from →trees →of the same species growing at different heights on the Himalaya, were found →in this country to possess different constitutional powers of resisting cold. Mr. Thwaites informs me that he has observed similar facts in

Ceylon,

Ceylon;

and

....

analogous observations have been made by Mr.H.

Watson on European species of plants brought from the Azores to →England; and I could give other cases. In regard to animals, several authentic

cases

instances

could be

given

adduced

of species →within historical times having largely extended their range from warmer to cooler latitudes, and conversely; but we do not positively know that these animals were strictly adapted to their native climate,

but

though

yet

in all

ordinary

ordi- nary