物种起源（英文全本）-全本TXT下载-(英)达尔文 精彩免费下载-isas

which I

had

dissected

from the

workers of

the

several

sizes.

With these

facts

before me,

I believe

that

natural

selection,

by acting

on the

fertile

parents,

could form

a species

which

should

regularly

produce

neuters,

either all

of large

size with

one form

of jaw, or

all of

small size

with jaws

having a

widely

different

structure;

or lastly,

and this

is our

climax of

difficulty,

one set of

workers of

one size

and

structure,

and

simultaneously