It has lately been asserted that two such distinct species as the hare and rabbit, when they can be got to breed together, produce offspring, which are highly fertile when crossed with one of the parent-species.

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.

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 Captain 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.
With our domesticated animals, the various races when crossed together are quite fertile; 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 at first produced perfectly fertile hybrids, or that the hybrids subsequently reared under domestication became quite fertile.
This latter alternative, which was first propounded by Pallas, seems by far the most probable, and can, indeed, hardly be doubted.