→ or perfectly fertile. 1866 1869 1872 |
fertile. 1859 1860 1861 |
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↑ 2 blocks not present in 1859 1860 1861 1866; present in 1869 1872 |
The
various races of each kind of domesticated animal
are quite fertile
when crossed together;
yet in many cases they are descended from two or more wild species.
From this fact we must conclude either that the aboriginal parent-species produced at first
perfectly fertile hybrids, or that the hybrids subsequently reared under domestication became quite fertile.
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→ seems 1861 1866 |
seems to me 1859 1860 |
which was first propounded by Pallas, seems 1869 |
which was first propounded by Pallas, seems by far 1872 |
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→ I have hardly any doubt of its truth, although it rests on no direct evidence. 1866 |
I am inclined to believe in its truth, although it rests on no direct evidence. 1859 1860 1861 |
can, indeed, hardly be doubted. 1869 1872 |
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→ almost certain that 1866 1869 1872 |
that 1859 1860 1861 |
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→ I have lately acquired decisive evidence that the crossed offspring from the Indian humped and common 1866 1869 1872 |
there is reason to believe that our European and the humped Indian 1859 1860 1861 |
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→
inter se
perfectly fertile; and from the observations by Rütimeyer on their important osteological differences, as well as from those
1866 1869 |
quite fertile together; but from facts communicated to me 1859 1860 1861 |
inter se
perfectly fertile; and from the observations by Rütimeyer on their important osteological differences, as well as from those
1872 |
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→ on their differences in habits, voice, constitution, &c., these two forms 1866 1869 1872 |
I think they 1859 1860 1861 |
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→ good and distinct species—as good as any in the world. 1866 |
distinct species. 1859 1860 1861 |
good and distinct species as any in the world. 1869 |
good and distinct species. 1872 |
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↑ 1 blocks not present in 1859 1860 1861 1866 1869; present in 1872 |
The same remarks may be extended to the two chief races of the pig.
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→ On this view 1859 1860 1861 1866 |
According to this view 1869 |
We must, therefore, either give up the belief 1872 |
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→ origin of many of our domestic animals, 1859 1860 1861 1866 |
origin of many domestic animals, 1869 |
universal sterility of species when crossed; or 1872 |
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→ either give up the belief of the almost universal sterility of distinct species of animals when crossed; or we must 1859 1860 1861 1866 1869 |
OMIT 1872 |
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