Origin of Species Variorum

→ often escape destruction. 1872

escape entire annihilation. 1866

escape much destruction. 1869

→ to have actually 1869 1872

that Mr. Bates has 1866

→ which 1869 1872

whether these be ranked as species or varieties, which 1866

→ varied in an extreme degree. 1869 1872

vary much. 1866

→ mocked another form of 1869 1872

mocks and 1866

→ the Leptalis first 1869 1872

in every case the Leptalis originally 1866

→ happens 1869 1872

arose which happened 1866

→ natural 1869 1872

the principle of natural 1866

→ and Trimen have likewise 1872

has recently 1866 1869

→ Africa, and with some other 1872

other cases could be given with other orders of 1866

other instances could be given with other orders of 1869

→ such case with 1872

instance of mimicry amongst 1866

case of mimicry amongst 1869

→ none 1872

no such cases 1866 1869

→ furnished with a 1872

that 1866 1869

→ which prey on them; hence 1872

hence 1866 1869

↑ 2 blocks not present in 1859 1860 1861 1872; present in 1866 1869

But to return to more ordinary cases of analogical resemblance: as members of distinct classes have often been adapted by successive slight modifications to live under nearly similar circumstances,— to inhabit, for instance, the three elements of land, air, and water,— we can perhaps understand how it is that a numerical parallelism has sometimes been observed between the subgroups in distinct classes. A naturalist, struck by a parallelism of this nature in any one class, by arbitrarily raising or sinking the value of the groups in other classes (and all our experience shows that their valuation is as yet arbitrary), could easily extend the parallelism over a wide range; and thus the septenary, quinary, quaternary, and ternary classifications have probably arisen.

↑ 2 blocks not present in 1866 1869 1872; present in 1859 1860 1861

As members of distinct classes have often been adapted by successive slight modifications to live under nearly similar circumstances,— to inhabit for instance the three elements of land, air, and water,— we can perhaps understand how it is that a numerical parallelism has sometimes been observed between the sub-groups in distinct classes. A naturalist, struck by a parallelism of this nature in any one class, by arbitrarily raising or sinking the value of the groups in other classes (and all our experience shows that this valuation has hitherto been arbitrary), could easily extend the parallelism over a wide range; and thus the septenary, quinary, quaternary, and ternary classifications have probably arisen.

four generations swarm over the whole country. Now if a member of one of these persecuted and rare groups were to assume a dress so like that of a well-protected species that it continually deceived the practised eyes of an entomologist, it would often deceive

predacious

predaceous

birds and insects, and thus →often escape destruction.

Mr. Bates

may almost be said →to have actually witnessed the process by which the mimickers have come so closely to resemble the mimicked; for he

shows

found

that some of the forms of

Leptalis,

Leptalis

→which mimic so many other butterflies, →varied in an extreme degree. In one district several varieties

occur,

occurred,

and of these one alone

resembles,

resembled

to a certain extent, the common Ithomia of the same district. In another district there

are

were

two or three varieties, one of which

was

much commoner than the others, and this closely →mocked another form of Ithomia. From

many facts

facts

of this nature, Mr. Bates concludes that →the Leptalis first

varied;

varies;

and

that, when

when

a variety →happens to resemble in some degree any common butterfly inhabiting the same district, this variety, from its resemblance to a

flourish-

flourishing

ing and

and

little-persecuted kind,

had

has

a better chance of escaping destruction from

predacious

predaceous

birds and insects, and

was

consequently oftener preserved;— "the less perfect degrees of resemblance being generation after generation eliminated, and only the others left to propagate their kind." So that here we have an excellent illustration of →natural selection.

Mr.

Messrs.

Wallace →and Trimen have likewise described several equally striking cases of

mimicry

imitation

in the Lepidoptera of the Malay

Archipelago,

Archipelago

and →Africa, and with some other insects. Mr. Wallace has also

given

described

detected

one →such case with birds, but we have →none with the larger

animals.

quadrupeds.

The much greater frequency of

mockery

mimicry

imitation

with insects than with other animals, is probably the consequence of their small size; insects cannot defend themselves, excepting indeed the kinds →furnished with a sting, and I have never heard of an instance of

these

such kinds

mocking other insects, though they are

mocked:

mocked;

insects cannot

escape

easily escape

by flight from the larger

animals;

animals

→which prey on them; hence they are reduced, like most weak creatures, to trickery and dissimulation. ↑ ↑

It should be observed that the process of imitation probably never commenced between forms widely dissimilar in colour. But starting with species already somewhat like each other, the closest resemblance, if beneficial, could readily be gained by the above means; and if the imitated form was subsequently and gradually modified through any agency, the imitating form would be led along the same track, and thus be altered to almost any extent, so that it might ultimately assume an appearance or colouring wholly unlike