Comparison with 1869 |
|
should be perfectly fertile. Again, with respect to the fertility in successive generations of the more fertile 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, torquatus, 1866 1869 1872 | torquatus 1859 1860 1861 |
...OMIT 1866 1869 1872 |
and with P. versicolor 1859 1860 |
and with P. versicolor, 1861 |
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.
|
It has lately been asserted that two such distinct species as the hare and rabbit, when they can be got to breed together, produce almost perfectly fertile offspring; but this statement is as yet very doubtful. The hybrids from the common and Chinese geese (A. cygnoides),
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.
1869 |
se
.
1859 1860 1861 1866 1872 |
This was effected by Mr. Eyton, who raised two hybrids from the same
parents, parents, 1866 1869 1872 | parents 1859 1860 1861 |
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
|
should be perfectly fertile. Again, with respect to the fertility in successive generations of the more fertile 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.
|
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. 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. 1860 1861 |
From the experiments lately made on a large scale in France, it seems that two such distinct species as the hare and rabbit, when they can be got to breed together, produce offspring almost perfectly fertile. 1866 |
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
|