Origin of Species Variorum

→ and become gradually 1859 1860 1861 1866

becoming at the same time 1869 1872

→ to any extent, 1859 1860 1861 1866

OMIT 1869 1872

→ this great amount of modification there would be no tendency 1866

this great amount of modification there will be no tendency 1859 1860 1861

this modification would not tend 1869

these modifications would not tend 1872

→ the ancient progenitor, 1859 1860 1861 1866

an early progenitor,— 1869

an early progenitor— 1872

→ had 1859 1860 1861 1866 1869

birds, and reptiles, had 1872

→ 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

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

in different members of a class, but 1859 1860 1861

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

bones of a limb might be shortened and

flattened

widened

to any extent, →and become gradually enveloped in thick membrane, so as to serve as a fin; or a webbed

hand

foot

might have all its bones, or certain

bones

bones,

lengthened to any extent,

with

and

the membrane connecting them

increased,

increased

→to any extent, so as to serve as a

wing:

wing;

yet

all →this great amount of modification there would be no tendency to alter the framework of

bones

the bones

or the relative connexion of the

~~several~~

several

parts. If we suppose that →the ancient progenitor, the archetype as it may be

called,—

called—

called,

of all mammals, →had its limbs constructed on the existing general pattern, for whatever purpose they served, we can at once perceive the plain signification of the homologous construction of the limbs throughout the

~~whole~~

whole

class. So with the mouths of insects, we have only to 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.