Origin of Species Variorum

→ now lost. 1866 1869 1872

lost. The presence of luminous organs in a few insects, belonging to different families and orders, offers a parallel case of difficulty. 1859 1860 1861

→ more closely, we 1869 1872

we 1866

→ the requisite nervous power 1866 1869

being supplied with nerves proceeding from different sources, 1872

→ being supplied through different nerves from widely different sources, and this is perhaps the most important of all the differences. 1869

(and this is perhaps the most important of all the differences) being supplied through different nerves from widely different sources. 1866

and this is perhaps the most important of all the differences. 1872

→ disappears, 1866 1869

of an organ, apparently the same, arising in several remotely allied species, disappears, 1872

→ group of fishes. 1869

fish. 1866

group of fishes. 1872

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

The presence of luminous organs in a few insects, belonging to different families and orders, offers a parallel case of difficulty.

→ a 1866 1869

under our present state of ignorance, a 1872

→ Other cases could be given; for instance in plants, the very curious contrivance of a mass of pollen-grains, borne on a foot-stalk with an adhesive gland, is apparently 1866 1869

In all these cases of two very distinct species furnished with apparently 1859 1860 1861

Other similar cases could be given; for instance in plants, the very curious contrivance of a mass of pollen-grains, borne on a foot-stalk with an adhesive gland, is apparently 1872

→ in Orchis and Asclepias,—genera almost as remote as is possible amongst flowering plants. 1866 1869

anomalous organ, it should be observed that, although the general appearance and function of the organ may be the same, yet some fundamental difference can generally be detected. 1859 1860 1861

in Orchis and Asclepias,— genera almost as remote as is possible amongst flowering plants; but here again the parts are not homologous. 1872

→ In all such cases of two species, far removed from each other in the scale of organisation, being furnished with similar anomalous organs, it should be observed that although the general appearance and function of the organ may be 1869

I am inclined to believe that in nearly the same way as two men have sometimes independently hit on the very same invention, so natural selection, working for the good of each being and taking advantage of analogous variations, has sometimes modified in very nearly 1859 1860 1861

In all these cases of two species, far removed from each other in the scale of organisation, being furnished with a similar anomalous organ, it should be observed that although the general appearance and function of the organ may be 1866

In all cases of beings, far removed from each other in the scale of organisation, which are furnished with similar and peculiar organs, it will be found that although the general appearance and function of the organs may be 1872

lead to the belief that

formerly

....

most fishes

had

formerly possessed

electric organs, which

most of

....

their modified descendants have →now lost. But when we look

closer to

the

subject,

subject

→more closely, we find in the several fishes provided with electric

organs,

organs

that these are situated in different parts of the

body,—

body,—that

that they

they

differ in construction, as in the arrangement of the plates, and, according to Pacini, in the process or means by which the electricity is

excited,—and

excited— and

excited—and

lastly, in →the requisite nervous power →being supplied through different nerves from widely different sources, and this is perhaps the most important of all the differences. Hence in the several

~~remotely allied~~

remotely allied

fishes furnished with electric organs, these cannot be considered as homologous, but only as analogous in function. Consequently there is no reason to suppose that they have been inherited from a common progenitor; for had this been the case they would have closely resembled each other in all respects. Thus the

~~greater~~

greater

difficulty →disappears, leaving only the lesser yet still great difficulty; namely, by what graduated steps these organs have

~~arisen and~~

arisen and

been developed in each separate → group of fishes. ↑ The luminous organs which occur

~~only~~

only

in a few insects, belonging to widely different

families,

families

and

orders, but

~~orders, and~~

orders, and

which are situated in different parts of

their bodies,

the body,

offer,

offer

→a difficulty almost exactly parallel with that of the electric organs. →Other cases could be given; for instance in plants, the very curious contrivance of a mass of pollen-grains, borne on a foot-stalk with an adhesive gland, is apparently the same →in Orchis and Asclepias,—genera almost as remote as is possible amongst flowering plants. →In all such cases of two species, far removed from each other in the scale of organisation, being furnished with similar anomalous organs, it should be observed that although the general appearance and function of the organ may be