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. ↑2 blocks not present in 1869 1872; present in 1859 1860 1861 1866 | A doctrine which originated with Pallas,
has been largely accepted by modern naturalists; namely, that most of our domestic animals have descended from two or more aboriginal
species, since commingled by intercrossing.
On this view, the aboriginal species must either at first have produced quite fertile hybrids, or the hybrids must have become in subsequent generations
quite fertile under domestication.
|
This latter
alternative, alternative, 1869 1872 | alternative 1859 1860 1861 1866 |
which was first propounded by Pallas, seems which was first propounded by Pallas, seems 1869 |
seems to me 1859 1860 |
seems 1861 1866 |
which was first propounded by Pallas, seems by far 1872 |
the most probable, and
can, indeed, hardly be doubted. can, indeed, hardly be doubted. 1869 1872 |
I am inclined to believe in its truth, although it rests on no direct evidence. 1859 1860 1861 |
I have hardly any doubt of its truth, although it rests on no direct evidence. 1866 |
It is, It is, 1866 1869 1872 | I believe, 1859 1860 1861 |
for instance,
almost certain that almost certain that 1866 1869 1872 |
that 1859 1860 1861 |
our dogs
are are 1869 1872 | have 1859 1860 1861 1866 |
descended from several wild stocks; yet, with perhaps the exception of certain indigenous domestic dogs of South America, all are quite fertile together; and
analogy makes me greatly doubt, whether the several aboriginal species would at first have freely bred together and have produced quite fertile hybrids. So again
I have lately acquired decisive evidence that the crossed offspring from the Indian humped and common 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 |
cattle are
inter se
perfectly fertile; and from the observations by Rütimeyer on their important osteological differences, as well as from those
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 |
by Mr.
Blyth Blyth 1866 1869 1872 | Blyth, 1859 1860 1861 |
on their differences in habits, voice, constitution, &c., these two forms on their differences in habits, voice, constitution, &c., these two forms 1866 1869 1872 |
I think they 1859 1860 1861 |
must be
regarded regarded 1866 1869 1872 | considered 1859 1860 1861 |
as
good and distinct species as any in the world. good and distinct species as any in the world. 1869 |
distinct species. 1859 1860 1861 |
good and distinct species—as good as any in the world. 1866 |
good and distinct species. 1872 |
↑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.
|
According to this view According to this view 1869 |
On this view 1859 1860 1861 1866 |
We must, therefore, either give up the belief 1872 |
of the
origin of many domestic animals, origin of many domestic animals, 1869 |
origin of many of our domestic animals, 1859 1860 1861 1866 |
universal sterility of species when crossed; or 1872 |
we must either give up the belief of the almost universal sterility of distinct species of animals when crossed; or we must
look at sterility,
not as an indelible characteristic, but as one capable of being removed by domestication. |