Comparison with 1861 |
|
hybrid animals, I hardly know of an instance in which two families of the same hybrid have been raised at the same time from different parents, so as to avoid the ill effects of close interbreeding. On the contrary, brothers and sisters have usually been crossed in each successive generation, in opposition to the constantly repeated admonition of every breeder. And in this case, it is not at all surprising that the inherent sterility in the hybrids should have gone on increasing. If we were to act thus, and pair brothers and sisters in the case of any pure animal, which from any cause had the least tendency to sterility, the breed would assuredly be lost in a
....... 1861 1866 1869 | very 1859 1860 |
few generations. |
|
Although I do not
know of any
thoroughly well-authenticated cases of perfectly fertile hybrid animals, I have
....... 1861 1866 1869 1872 | some 1859 1860 |
reason to believe that the hybrids from Cervulus vaginalis and Reevesii, and from Phasianus colchicus with P. torquatus
and with P. versicolor, and with P. versicolor, 1861 |
and with P. versicolor 1859 1860 |
OMIT 1866 1869 1872 |
are perfectly fertile. ↑1 blocks not present in 1859 1860 1861 1866 1869; present in 1872 | M. Quatrefages states that the hybrids from two moths (Bombyx cynthia and arrindia) were proved in Paris to be fertile
inter
se
for eight generations.
|
There is no doubt that these three pheasants, namely, the common, the true ring-necked, and the Japan, intercross, and are becoming blended together in the woods of several parts of England.
The hybrids from the common and Chinese geese (A.
cignoides), cignoides), 1861 | cygnoides), 1859 1860 1866 1869 1872 |
species which are so different that they are generally ranked in distinct genera, have often bred in this country with either pure parent, and in one single instance they have bred
inter
se
.
This was effected by Mr. Eyton, who raised two hybrids from the same parents
but from different hatches; and from these two birds he raised no less than eight
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 fertile.
↑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.
|
|
A doctrine which originated with Pallas,
has been
|
hybrid animals, I hardly know of an instance in which two families of the same hybrid have been raised at the same time from different parents, so as to avoid the ill effects of close interbreeding. On the contrary, brothers and sisters have usually been crossed in each successive generation, in opposition to the constantly repeated admonition of every breeder. And in this case, it is not at all surprising that the inherent sterility in the hybrids should have gone on increasing. If we were to act thus, and pair brothers and sisters in the case of any pure animal, which from any cause had the least tendency to sterility, the breed would assuredly be lost in a
very very 1859 1860 | very 1861 1866 1869 |
few generations. |
|
Although I
do not do not 1859 1860 1861 1866 1869 | do not 1872 |
know of
any any 1859 1860 1861 1866 1869 | hardly any 1872 |
thoroughly well-authenticated cases of perfectly fertile hybrid animals, I have
some some 1859 1860 | some 1861 1866 1869 1872 |
reason to believe that the hybrids from Cervulus vaginalis and Reevesii, and from Phasianus colchicus with P.
torquatus torquatus 1859 1860 1861 | torquatus, 1866 1869 1872 |
and with P. versicolor and with P. versicolor 1859 1860 |
and with P. versicolor, 1861 |
OMIT 1866 1869 1872 |
are perfectly fertile. ↑1 blocks not present in 1859 1860 1861 1866 1869; present in 1872 | M. Quatrefages states that the hybrids from two moths (Bombyx cynthia and arrindia) were proved in Paris to be fertile
inter
se
for eight generations.
|
The hybrids from the common and Chinese geese (A.
cygnoides), cygnoides), 1859 1860 1866 1869 1872 | cignoides), 1861 |
species which are so different that they are generally ranked in distinct genera, have often bred in this country with either pure parent, and in one single instance they have bred
inter
se
.
se
.
1859 1860 1861 1866 1872 |
se.
1869 |
This was effected by Mr. Eyton, who raised two hybrids from the same
parents parents 1859 1860 1861 | parents, 1866 1869 1872 |
but from different hatches; and from these two birds he raised no less than
eight eight 1859 1860 1861 1869 1872 | eigth 1866 |
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
fertile. fertile. 1859 1860 1861 |
or perfectly fertile. 1866 1869 1872 |
|
A doctrine which originated with
Pallas, Pallas, 1859 1860 1861 | Pallas 1866 |
has been
|