| → as females more rarely 1859 1860 1861 1866 1869 |
| more rarely to the females, as they seldom 1872 |
|
| → OMIT 1869 1872 |
| may here add, that I 1859 1860 1861 1866 |
|
| → only give 1869 |
| only briefly give 1859 1860 1861 1866 |
| give only 1872 |
|
| → the same 1869 1872 |
| several of the 1859 1860 1861 1866 |
|
| → differ 1859 1860 1861 1866 1869 |
| of the same species differ 1872 |
|
| → belonging to 1869 |
| of 1859 1860 1861 1866 |
| belonging to other 1872 |
|
| → birds within 1859 1860 1861 1866 1869 |
| with birds the individuals of 1872 |
|
| → country vary in a remark- ably small degree, 1869 |
| country vary in a remarkably small degree, 1859 1860 1861 1866 |
| species, inhabiting the same country, vary extremely little, 1872 |
|
|
remarkable manner in comparison with
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,
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
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
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;
I
→OMIT
particularly attended to Mr.
remark, whilst investigating this Order, and I am fully convinced that the rule almost
holds
I shall, in
future work, give a list of
more remarkable cases; I will here
→only 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 word, very important structures, and they differ extremely little even in
genera; but in the several species of one genus, Pyrgoma, these valves present a marvellous amount of
the homologous valves in the different species being sometimes wholly unlike in shape; and the amount of variation in the individuals of
→the same
species is so great, that it is no exaggeration to state that the varieties
→differ
more from each other in the characters
these important
than do
species
→belonging to
distinct genera. |
|
| As
→birds within
the same
→country vary in a remark- ably small degree,
|
