物种起源（英文全本）-最新章节-古代 (英)达尔文-全集TXT下载

proves

that with

animals,

as with

plants,

any amount

of

modification

in

structure

can be

effected

by the

accumulation

of

numerous,

slight,

and as we

must call

them

accidental,

variations,

which are

in any

manner

profitable,

without

exercise

or habit

having

come into

play. For

no amount

of

exercise,

or habit,

or

volition,

in the

utterly

sterile

members of

a

community

could

possibly

have

affected

the

structure