Origin of Species Variorum

→ exactly 1859 1860 1861

(and this might often be of advantage to a species) exactly 1866

OMIT 1869 1872

→ species, that the child 1859 1860 1861 1866

OMIT 1869 1872

→ at a very early age 1859 1860 1861 1866

OMIT 1869 1872

→ with its parents, in accordance with their similar habits. 1859 1860 1861 1866

as their parents. 1869 1872

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

Again, with respect to the singular fact of so many terrestrial and fresh-water animals not undergoing any metamorphosis, whilst the marine members of the same classes pass through various transformations, Fritz Müller has suggested that if an animal during a long succession of generations had to change its habits from living in the sea to living on the land or in fresh-water, it would be a great advantage to its descendants during their modification if they were to lose their metamorphoses; for it is not probable that places well adapted for both the larval and mature stages, under such new and greatly changed habits of life, could be found unoccupied or ill-occupied by other organisms.

→ to 1859 1860 1861

of an animal to 1869 1872

→ in any degree 1859 1860 1861

slightly 1869 1872

→ manner, 1859 1860 1861 1869

plan, or if it profited a larva already different from its parent to change still further, 1872

→ then, 1859 1860 1861 1872

or if it profited a larva already widely different from its parent to change still further, then, 1869

→ larvæ might easily 1859 1860

larvæ might 1861

the larvæ might 1869 1872

→ different to any conceivable extent 1859 1860 1861

more and more different 1869 1872

→ parents. 1859 1860 1861

parents to any conceivable extent. 1869 1872

→ might, 1859 1860 1861

in the larvæ might, 1869

in the larva might, 1872

→ differ 1859 1860 1861

come to differ 1869 1872

→ we have seen to be 1859 1860 1861

is 1869 1872

→ said to be 1859 1860 1861

OMIT 1869 1872

→ on this earth have to be classed together, 1859 1860 1861

on this earth, have to be classed together, 1866

can be arranged within a few great classes; 1869 1872

→ have 1859 1860 1861 1866

within each class have, according to our theory, formerly 1869

within each class have, according to our theory, 1872

→ by the finest 1859 1860

by fine 1861 1866

together by fine 1869 1872

→ on my view 1859 1860 1861

on this view 1866

OMIT 1869 1872

from their following →exactly the same habits of life with their parents; for in this case, it would be indispensable for

their

the

existence

that

they

the

→species, that the child should be modified →at a very early age in the same manner →with its parents, in accordance with their similar habits. ↑ Some further explanation, however, of the embryo not undergoing any metamorphosis is perhaps requisite. If, on the other hand, it profited the young →to follow habits of life →in any degree different from those of

the parent-form,

their parent,

and consequently to be constructed

a slightly different →manner, →then, on the principle of inheritance at corresponding ages, the

~~active~~

active

young or →larvæ might easily be rendered by natural selection →different to any conceivable extent from their →parents.

~~Such~~

Such

Differences

differences

→might, also, become correlated with successive stages of

its development;

development;

so that the

larvæ

larva,

larvæ,

in the first stage, might →differ greatly from the

larva

larvæ

in the second stage, as →we have seen to be the case with

many animals.

cirripedes.

The adult might

also become

become

fitted for sites or habits, in which organs of locomotion or of the senses, &c., would be useless; and in this case the

~~final~~

final

metamorphosis would be →said to be retrograde.

As all the organic beings, extinct and recent, which have ever

lived,

lived

→on this earth have to be classed together, and as all →have been connected →by the finest gradations, the best,

or,

and,

or indeed,

if our collections were nearly perfect, the only possible arrangement, would be

genealogical;

genealogical.

descent

Descent

being →on my view the hidden bond of connexion which naturalists have been seeking under the term of the

Natural

natural

System.

system.

On this view we can understand how it is that, in the eyes of most

natu- ralists,

naturalists,

the structure of the embryo is even more important for classification than that of the adult. For the embryo is the animal in its less modified state;