Origin of Species Variorum

→ OMIT 1869 1872

at the same time and place 1866

→ I have now explained how, 1866 1869 1872

Thus, 1859 1860 1861

→ tools, whilst man works 1866 1869 1872

weapons, and not 1859

tools, and not 1860 1861

↑ 1 blocks not present in 1866 1869 1872; present in 1859 1860 1861

And nature has, as I believe, effected this admirable division of labour in the communities of ants, by the means of natural selection.

→ must 1866 1869 1872

am bound to 1859 1860 1861

→ to this conclusion. 1872

of the fact. 1859 1860 1861 1866 1869

→ may 1869 1872

in structure can 1859 1860 1861 1866

→ spontaneous 1869 1872

and as we must call them accidental, 1859 1860 1861

and spontaneous 1866

→ peculiar habits confined to the workers or sterile females, however long they might be followed, could not possibly 1869 1872

no amount of exercise, or habit, or volition, in the utterly sterile members of a community could possibly have 1859

no amount of exercise, or habit, or volition, in the utterly sterile members of a community could possibly 1860 1861

no amount of exercise, or habit, or volition, in the utterly sterile members of a community, could possibly 1866

→ males and fertile females, 1872

structure or instincts of the fertile members, 1859 1860 1861 1866

males and fertile female, 1869

→ inherited habit, as advanced by Lamarck. 1869 1872

Lamarck. 1859 1860

inherited habit advanced by Lamarck. 1861 1866

→ in this chapter briefly 1866 1869 1872

briefly in this chapter 1859 1860 1861

→ there is no real 1869 1872

I can see no 1859 1860 1861 1866

→ to any extent slight modifications of instinct which are 1869 1872

slight modifications of instinct to any extent, 1859 1860 1861 1866

appearing →OMIT under two or even three distinct female forms; and by Fritz

Müller,

of certain Brazilian crustaceans likewise appearing under two widely distinct male forms. But

the

this

subject need not here be discussed.

→I have now explained how, as I believe, the wonderful fact of two distinctly defined castes of sterile workers existing in the same nest, both widely different from each other and from their parents, has originated. We can see how useful their production may have been to a social community of

insects,

ants,

on the same principle that the division of labour is useful to civilised man.

As ants

Ants, however,

work by inherited instincts and by inherited

tools

organs

or →tools, whilst man works by acquired knowledge and manufactured

instruments,

perfect

division

labour

could

effected

with

them

only

the

workers

being

sterile;

for

had

they

been

fertile,

they

would

have

intercrossed,

and

their

instincts

and

structure

would

have

become

blended.

↑ But I →must confess, that, with all my faith in

this principle,

natural selection,

I should never have anticipated that

natural selection

this principle

could have been efficient in so high a degree, had not the case of these neuter insects

convinced

led

me →to this conclusion. I have, therefore, discussed this case, at some little but wholly insufficient length, in order to show the power of natural selection, and likewise because this is by far the most serious special

difficulty,

difficulty

which my theory has encountered. The case, also, is very interesting, as it proves that with animals, as with plants, any amount of modification →may be effected by the accumulation of numerous, slight, →spontaneous variations, which are in any

manner

way

profitable, without exercise or habit having

come

been brought

into play. For →peculiar habits confined to the workers or sterile females, however long they might be followed, could not possibly

affected

affect

the →males and fertile females, which alone leave descendants. I am surprised that no one has

advanced

hitherto advanced

this demonstrative case of neuter insects, against the well-known doctrine of →inherited habit, as advanced by Lamarck.

Summary .—

Summary. —

Summary .

I have endeavoured →in this chapter briefly to show that the mental qualities of our domestic animals vary, and that the variations are inherited. Still more briefly I have attempted to show that

in-

....

stincts

instincts

vary slightly in a state of nature. No one will dispute that instincts are of the highest importance to each animal.

There- fore

Therefore

→there is no real difficulty, under changing conditions of life, in natural selection accumulating →to any extent slight modifications of instinct which are in any

useful direction.

way useful.

some

many

cases habit or use and disuse have probably come into play. I do not pretend that the facts given in this chapter strengthen in any great degree my theory; but none of the cases of difficulty, to the best of my judgment, annihilate it. On the other hand, the fact that instincts