Origin of Species Variorum

→ comparison 1859 1860 1861 1866 1869

one species or in a few species in comparison 1872

→ bat's wing 1859 1861 1866

bats wing 1860

wing of the bat 1869

wing 1872

→ most 1859 1860 1861 1866 1869

bat is a most 1872

→ of bat had its 1859 1860 1861 1866

had 1869 1872

→ as females more rarely 1859 1860 1861 1866 1869

more rarely to the females, as they seldom 1872

→ may here add, that I 1859 1860 1861 1866

OMIT 1869 1872

→ only briefly give 1859 1860 1861 1866

only give 1869

give only 1872

here introduced. I can only state my conviction that it is a rule of high generality. I am aware of several causes of error, but I hope that I have made due allowance for them. It should be understood that the rule by no means applies to any part, however unusually developed, unless it be unusually developed in →comparison with the same part in

many closely

closely

allied species. Thus, the →bat's wing

a →most abnormal structure in the class

of mammalia;

of mammals,

mammalia;

but the rule would not

~~here~~

apply

~~because~~

here,

because the

whole group of bats

possesses

having

wings;

wings:

it would apply only if some one species →of bat had its wings developed in

some

remarkable manner in comparison with

~~the~~

the

other species of the same genus. The rule applies very strongly in the case of secondary sexual characters, when displayed in any unusual manner. The term, secondary sexual characters, used by Hunter,

relates

applies

to characters which are attached to one sex, but are not directly connected with the act of reproduction. The rule applies to males and females; but →as females more rarely offer remarkable secondary sexual

characters.

characters,

~~applies~~

applies

~~more~~

~~rarely~~

rarely

~~them.~~

them.

The rule being so plainly applicable in the case of secondary sexual characters, may be due to the great variability of these characters, whether or not displayed in any unusual

manner—

manner —

of which fact I think there can be little doubt. But that our rule is not confined to secondary sexual characters is clearly shown in the case of hermaphrodite cirripedes;

~~and~~

and

I →may here add, that I particularly attended to Mr.

Waterhouses

Waterhouse's

remark, whilst investigating this Order, and I am fully convinced that the rule almost

always

invariably

holds

good.

good

~~with~~

with

~~cirripedes.~~

cirripedes.

I shall, in

future work, give a list of

all the

the

more remarkable cases; I will here →only briefly give one, as it illustrates the rule in its largest application. The opercular valves of sessile cirripedes (rock barnacles) are, in every sense of the