Origin of Species Variorum

→ by 1872

to be the case by any 1869

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

My impression is, that the effect is extremely small in the case of animals, but perhaps rather more in that of plants.

→ In the following cases the conditions seem to have produced some slight definite effect: 1869 1872

Some little influence may be attributed to climate, food, &c.: thus, 1859 1860 1861 1866

→ are 1859 1860 1869 1872

vary and become 1861 1866

→ a greater depth; but this certainly does not always hold good. 1872

greater depths. 1859 1860 1861 1866

a greater depth; but these statements have lately been disputed. 1869

→ near the coast or on islands; and Wollaston is convinced that residence near the sea affects the colours of insects. 1872

on islands or near the coast. 1859 1860 1861

on islands or near the coast. So with insects: Wollaston is convinced that residence near the sea affects their colours. 1866

on islands or near the coast; and Wollaston is convinced that residence near the sea affects the colours of insects. 1869

→ Moquin-Tandon gives a list of plants which, when growing near the sea-shore, have their leaves in some degree fleshy, though not elsewhere fleshy. 1872

Moquin-Tandon gives a list of plants which when growing near the sea-shore have their leaves in some degree fleshy, though not elsewhere fleshy. 1859 1860 1861 1869

Several other such cases could be given. 1866

→ definite action of the conditions 1869 1872

conditions 1859 1860 1861 1866

→ further north they 1869 1872

more severe the climate is under which they have 1859 1860 1861 1866

→ similar varieties 1869 1872

the same variety 1859 1860 1861 1866

→ from the same species under external 1869 1872

under 1859 1860 1861 1866

→ external 1869 1872

species under the same 1859 1860

species under apparently the same 1861 1866

→ to lay less 1872

to lay very little 1859 1860 1861 1866

not to lay much 1869

→ action 1859 1860 1861 1866 1872

and definite action 1869

→ surrounding conditions, than on a tendency to vary, due to causes of which we are quite ignorant. 1872

conditions of life. 1859 1860 1861 1866

conditions of life; but I fully admit that strong arguments of a general nature may be advanced on the other side. 1869

→ one sense 1869 1872

a far-fetched sense, however, 1866

→ either directly or indirectly, but 1872

but 1866 1869

→ OMIT 1869 1872

it depends on the nature of 1866

→ when man is the selecting agent, we clearly see that the 1869 1872

we see in selection by man, that these 1866

→ variability is in some manner excited, but it is 1872

the conditions under domestication causing the variability, and 1866

the conditions cause the variability; 1869

some

....

reason to believe that in the course of time the effects have been greater than can be proved →by clear evidence. ↑ But we may safely conclude that the innumerable complex co-adaptations of structure, which we see throughout nature between various organic beings, cannot be attributed simply to such action. →In the following cases the conditions seem to have produced some slight definite effect: E. Forbes

speaks confidently

asserts

that shells at their southern limit, and when living in shallow water, →are more brightly coloured than those of the same species

further

from further

north or from →a greater depth; but this certainly does not always hold good.

Gould

Mr. Gould

believes that birds of the same species are more brightly coloured under a clear atmosphere,

that

than

when living →near the coast or on islands; and Wollaston is convinced that residence near the sea affects the colours of insects. →Moquin-Tandon gives a list of plants which, when growing near the sea-shore, have their leaves in some degree fleshy, though not elsewhere fleshy. These slightly varying organisms are interesting in as far as they present characters analogous to those possessed by the species which are confined to similar conditions.

When a variation is of the

slighest

slightest

use to

any

being, we cannot tell how much

of it

....

to attribute to the accumulative action of natural selection, and how much to the →definite action of the conditions of life. Thus, it is well known to furriers that animals of the same species have thicker and better fur the →further north they

lived;

live;

but who can tell how much of this difference may be due to the warmest-clad individuals having been favoured and preserved during many generations, and how much to the

direct

....

action of the severe climate? for it would appear that climate has some direct action on the hair of our domestic quadrupeds.

Instances could be given of →similar varieties being produced →from the same species under external conditions of life as different as can well be conceived; and, on the other hand, of

different

dissimilar

varieties being produced

from

under apparently

the same →external conditions. Again, innumerable instances are known to every

naturalist

naturalist,

of species keeping true, or not varying at all, although living under the most opposite climates. Such considerations as these incline me →to lay less weight on the direct →action of the →surrounding conditions, than on a tendency to vary, due to causes of which we are quite ignorant.

In →one sense the conditions of life may be said, not only to cause variability, →either directly or indirectly, but likewise to include natural

selection;

selection,

for →OMIT the conditions

whether

determine whether

this or that variety shall

be preserved.

survive.

But →when man is the selecting agent, we clearly see that the two elements of change are

essenitally

....

distinct; →variability is in some manner excited, but it is