See page in:
1859
1860
1861
1866
1869
1872

Compare with:
1859
1860
1861
1869
1872

or perfectly fertile. 1866 1869 1872
fertile. 1859 1860 1861

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.

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

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

almost certain that 1866 1869 1872
that 1859 1860 1861

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

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

on their differences in habits, voice, constitution, &c., these two forms 1866 1869 1872
I think they 1859 1860 1861

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

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.

On this view 1859 1860 1861 1866
According to this view 1869
We must, therefore, either give up the belief 1872

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

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

less than
eight
eigth
hybrids (grandchildren of the pure geese) from one nest. In India, however, these cross-bred geese must be far more fertile; for I am assured by two eminently capable judges, namely Mr. Blyth and Capt. Hutton, that whole flocks of these crossed geese are kept in various parts of the country; and as they are kept for profit, where neither pure parent-species exists, they must certainly be highly or perfectly fertile.
A doctrine which originated with
Pallas,
Pallas
has been largely accepted by modern naturalists; namely, that most of our domestic animals have descended from two or more
aboriginal
wild
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
generation
quite fertile under domestication. This latter
alternative,
alternative
seems the most probable, and I have hardly any doubt of its truth, although it rests on no direct evidence.
I believe,
It is,
for instance, almost certain that our dogs
are
have
descended from several wild stocks; yet, with perhaps the exception of certain indigenous domestic dogs of South America, all are quite fertile together;
but
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 cattle are inter se perfectly fertile; and from the observations by Rütimeyer on their important osteological differences, as well as from those by Mr.
Blyth,
Blyth
on their differences in habits, voice, constitution, &c., these two forms must be
considered
regarded
as good and distinct species—as good as any in the world. On this view of the origin of many of our domestic animals, we must either give up the belief of the almost universal sterility of distinct species of animals when crossed; or we must