Origin of Species Variorum

by too close interbreeding having been avoided.

Now let us turn to the results arrived at by a third most experienced hybridiser, namely, the Hon. and Rev. W. Herbert. He is as emphatic in his conclusion that some hybrids are perfectly fertile—as .. fertile as the pure parent-species—as .. are Kölreuter and Gärtner that some degree of sterility between distinct species is a universal law of nature. He experimented on some of the very same species as did Gärtner. The difference in their results may, I think, be in part accounted for by Herbert's great horticultural skill, and by his having hot-houses at his command. Of his many important statements I will here give only a single one as an example, namely, that "every ovule in a pod of Crinum capense fertilised by C. revolutum produced a plant, which .. I never saw to occur in a case of its natural fecundation." So that here we have perfect or even more than commonly perfect, fertility in a first cross between two distinct species.

This case of the Crinum leads me to refer to a .. singular fact, namely, that .. individual plants of certain species of Lobelia, Verbascum and Passiflora, can easily be fertilised by .. pollen from a distinct species, but not by pollen from the same plant, though this pollen can be proved to be perfectly sound by fertilising other plants or species. In the genus Hippeastrum, in Corydalis as shown by Professor Hildebrand, in various orchids as shown by Mr. Scott and Fritz Müller, all the individuals are in this peculiar condition. ↑ So that with some species, certain abnormal individuals, and in other species all the individuals, ... can actually be hybridised much more readily than they can be fertilised by pollen from the same individual plant!