Origin of Species Variorum

→ will 1859 1861 1866 1869 1872

acting on some originally created form, will 1860

→ to have been 1859 1860 1861 1866

OMIT 1869 1872

→ a certain extent 1859 1860 1861 1866

have been partially 1869

have become partially 1872

→ the comparison not 1859 1860 1861 1866 1869

serial homologies, or the comparison 1872

→ in different members of a class, but 1859 1860 1861

or organ in different members of the same class, but 1866

or organs in different members of the same class, but 1869

or organs in the same individual, and not 1872

→ the same individual. 1859 1860 1861 1866 1869

different members of the same class. 1872

→ each member of the vertebrate and articulate 1859 1860 1861

all the members of the vertebrate 1866

all the higher vertebrate 1869 1872

→ We see the same law in comparing 1859 1860 1861

So it is with 1866 1869 1872

→ in embryonic crustaceans and in many other animals, and in flowers, 1859 1860 1861

in flowers during their early development, as well as in crustaceans and many other animals during their embryonic states, 1866

during the early or embryonic stages of development in flowers, 1869 1872

→ that 1859 1860 1861 1866

as well as in crustaceans and many other animals, that 1869 1872

suppose that their common progenitor had an upper lip, mandibles, and two

pairs

pair

of maxillæ, these parts being perhaps very simple in form; and then natural

selection,

selection

→will account for the infinite diversity in

the structure

structure

and

functions

function

of the mouths of insects. Nevertheless, it is conceivable that the general pattern of an organ might become so much obscured as to be finally lost, by the

reduction

atrophy

and ultimately by the complete abortion of certain parts, by the

fusion

soldering together

of other parts, and by the doubling or multiplication of others,—

varia- tions

variations

which we know to be within the limits of possibility. In the paddles of the

gigantic extinct

extinct gigantic

sea-lizards, and in the mouths of certain suctorial crustaceans, the general pattern seems →to have been thus to →a certain extent obscured.

There is another and equally curious branch of

our present

our

the present

subject; namely, →the comparison not of the

different

same

parts

part

→in different members of a class, but of the

same

different

parts or organs in →the same individual. Most physiologists believe that the bones of the skull are

homologous—

homologous with—

that

is,

correspond in number and in relative

connexion—

connexion with—

with the

the

elemental parts of a certain number of vertebræ. The anterior and posterior limbs in →each member of the vertebrate and articulate classes are plainly homologous. →We see the same law in comparing the wonderfully complex jaws and legs

crustaceans. It is familiar to almost every one, that in a flower the relative position of the sepals, petals, stamens, and pistils, as well as their intimate structure, are intelligible on the view that they consist of metamorphosed leaves, arranged in a spire. In monstrous plants, we often get direct evidence of the possibility of one organ being transformed into another; and we can actually

see,

see

→in embryonic crustaceans and in many other animals, and in flowers, →that organs, which when mature