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I am strengthened in this conviction by a remarkable statement repeatedly made by Gartner, namely, that if even the less fertile hybrids be artificially fertilised with hybrid pollen of the same kind, their fertility, notwithstanding the frequent ill effects from manipulation, sometimes decidedly increases, and goes on increasing.
Hence when he visited a tribe, they used to bring him the seed which they intended to sow next year, and he fertilised it by shaking over it the women's necklaces, which had been previously dipped in a special mixture.
The mansion was situated in such a way that the sun, falling on it as into a funnel, dried up, warmed, and fertilised the mist which the verdant screen could not prevent the river wind from carrying there every morning and evening.
The whole literature of modern biology, the whole of our present zoology and botany, morphology and physiology, anthropology and psychology, are pervaded and fertilised by the theory of descent.
The soil, being of volcanic origin, is readily fertilised by moisture, and at once produces some kind of vegetation. This adds of course greatly to the effect of colour, which in the rocks themselves is extremely beautiful, especially at sunrise and sunset.
The earliest of the books which may be placed in this category, "On the Various Contrivances by which Orchids are Fertilised by Insects," was published in 1862, and whether we regard its theoretical significance, the excellence of the observations and the ingenuity of the reasonings which it records, or the prodigious mass of subsequent investigation of which it has been the parent, it has no superior in point of importance.
Weismannism not only retained the principle of utility and selection, but made it the only principle, rejecting entirely the action of external conditions as a cause of congenital modifications, i.e. of characters whose development is predetermined in the fertilised ovum.
Herbert, a most trustworthy authority, not only asserts as the result of his own observations and experiments that many hybrids are quite as fertile as the parent species, but he goes so far as to assert that the particular plant Crinum capense is much more fertile when crossed by a distinct species than when fertilised by its proper pollen!
In the genus Hippeastrum, in Corydalis as shown by Professor Hildebrand, in various orchids as shown by Mr. Scott and Fritz Muller, 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!
The gametes of the female each carry one X red chromosome, of those of the male half carry an X white chromosome, and half the Y white chromosome. The fertilised female ova therefore carry an X red chromosome + an X white chromosome, the male producing ova one X red chromosome and one Y white chromosome.
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