whether there had been more or less modification, the
principle of inheritance would keep the forms together which were allied in the greatest number of points. In tumbler pigeons, though some
sub-varieties differ from the others sub-varieties differ from the others 1859 1860 1861 1866 |
of the sub-varieties differ 1869 1872 |
in the important character of having a longer
beak, yet all are kept together from having the common habit of tumbling; but the short-faced breed has nearly or quite lost this habit;
nevertheless, without any
reasoning or thinking reasoning or thinking 1859 1860 1861 1866 |
thought 1869 1872 |
on the subject, these tumblers are kept in the same group, because allied in blood and alike in some other respects. If it could be proved that the Hottentot had descended from the Negro, I think he would be classed under the Negro group, however much he might differ in colour and other important characters from negroes. |
With species in a state of nature, every naturalist has in fact brought descent into his classification; for he includes in his lowest grade,
or or 1859 1860 1861 1866 | or 1869 1872 |
that of
a a 1859 1860 1861 1866 | the 1869 | a 1872 |
species, the two sexes; and how enormously these sometimes differ in the most important characters, is known to every naturalist: scarcely a single fact can be predicated in common of the
males males 1859 1860 1861 | adult males 1866 1869 1872 |
and hermaphrodites of certain cirripedes,
when adult, when adult, 1859 1860 1861 | when adult, 1866 1869 1872 |
and yet no one dreams of separating them. ↑1 blocks not present in 1859 1860 1861; present in 1866 1869 1872 | As soon as the three Orchidean forms, Monachanthus,
Myanthus, and Catasetum, which had previously been ranked as three distinct genera, were known to be sometimes produced on the same plant, they were immediately considered as varieties; and
now I have been able to show that they are
the male, female, and hermaphrodite forms of the same species.
|
The naturalist includes as one species the
several several 1859 1860 1861 1866 | various 1869 1872 |
larval stages of the same individual, however much they may differ from each other and from the
adult; adult; 1859 1860 1861 1866 | adult, 1869 1872 |
as
he likewise includes he likewise includes 1859 1860 1861 |
he likewise does 1866 |
well as 1869 1872 |
the so-called alternate generations of Steenstrup, which can only in a technical sense be considered as the same individual. He includes
monsters; monsters; 1859 1860 1861 | monsters 1866 1869 1872 |
he includes he includes 1859 1860 1861 | and 1866 1869 1872 |
varieties, not
solely because they closely resemble solely because they closely resemble 1859 1860 1861 |
because they may closely resemble 1866 |
from their partial resemblance to 1869 1872 |
the parent-form, but because they are descended from it. He who believes that the cowslip is descended from the primrose, or conversely, ranks them together as a single species, and gives a single definition. As soon as three Orchidean forms (Monochanthus, Myanthus, and Catasetum), which had previously
been ranked as three distinct genera, were known to be sometimes produced on the same spike, they were immediately included as a single species. ↑5 blocks not present in 1860 1861 1866 1869 1872; present in 1859 | But it may be asked, what ought we to do, if it could be proved that one species of kangaroo had been produced, by a long course of modification, from a bear?
Ought we to rank this one species with bears, and what should we do with the other species?
The supposition is of course preposterous; and I might answer by the
argumentum
ad
hominem
,
and ask what should be done if a perfect kangaroo were seen to come out of the womb of a bear?
According to all analogy, it would be ranked with bears; but then assuredly all the other species of the kangaroo family would have to be classed under the bear genus.
The whole case is preposterous; for where there has been close descent in common, there will certainly be close resemblance or affinity.
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