Origin of Species Variorum

→ branching off of the species 1859 1860 1861 1866

species branched off 1869 1872

→ In connexion with the present subject, I will make only two other remarks. 1859 1860 1861 1866

In connection with the present subject, I will make only two other remarks. 1869

I think it will be admitted by naturalists, without my entering on details, that secondary sexual characters are highly variable. 1872

→ I think it will 1859 1860 1861 1866 1869

It will also 1872

→ without my entering on details, that 1859 1860 1861 1866 1869

that species of the same group differ from each other more widely in their 1872

→ are very variable; I think it also will be admitted that species of the same group differ from each other more widely in their 1859 1860 1861 1866 1869

than in other parts of their organisation: compare, for instance, the amount of difference between the males of gallinaceous birds, in which 1872

→ than in other parts of their organisation; compare, for instance, 1859 1860 1861 1866 1869

are strongly displayed, with 1872

→ males of gallinaceous birds, in which secondary sexual characters are strongly displayed, with the amount of difference between their females; and the truth of this proposition will be granted. 1859 1860 1861 1866

males of gallinaceous birds, in which secondary sexual characters are strongly displayed, with the amount of difference between the females; and the truth of this proposition will be granted. 1869

females. 1872

→ parts of the organisation; for secondary sexual characters have been 1859 1860 1861 1866 1869

for they are 1872

→ their sexual characters, 1859 1860 1861 1866 1869

these 1872

→ parts of their structure. 1859 1860 1861 1866 1869

respects. 1872

since

within

the period

when

the →branching off of the species from a common progenitor, it is probable that they should still often be in some degree

variable,—

variable, —

at least more variable than those parts of the

organization

organisation

which have for a very long period remained constant.

Secondary

Sexual

Characters

Variable .—

Variable .

→In connexion with the present subject, I will make only two other remarks. →I think it will be

admitted

admitted,

→without my entering on details, that secondary sexual

characters,

characters

→are very variable; I think it also will be admitted that species of the same group differ from each other more widely in their secondary sexual

characters

characters,

→than in other parts of their organisation; compare, for instance, the amount of difference between the →males of gallinaceous birds, in which secondary sexual characters are strongly displayed, with the amount of difference between their females; and the truth of this proposition will be granted. The cause of the original variability of

these

secondary sexual

characters is not manifest; but we can see why

they

these characters

should not have been rendered as constant and uniform as

others,

other

→parts of the organisation; for secondary sexual characters have been accumulated by sexual selection, which is less rigid in its action than ordinary selection, as it does not entail death, but only gives fewer offspring to the less favoured males. Whatever the cause may be of the variability of secondary sexual characters, as they are highly variable, sexual selection will have had a wide scope for action, and may thus

~~readily~~

readily

have

suc- ceeded

succeeded

in giving to the species of the same group a greater amount of difference in →their sexual characters, than in other →parts of their structure.

It is a remarkable fact, that the secondary

~~sexual~~

sexual

differences between the two sexes of the same species