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Again Mr. Mivart writes: Darwin gives a series of the most wonderful and minute contrivances, by which the visits of insects are utilised for the fertilisation of orchids structures so wonderful that nothing could well be more so, except the attribution of their origin to minute, fortuitous, and indefinite variations.
And those tears appeared to lay the dust of so many pleasant sins, and promise fertilisation of so heavy a crop of virtue, that by inevitable action of the law of contraries the two friends found it more than ever difficult to say farewell and part that night. Now looking back on all that, viewing it calmly in perspective, her action and attitude struck Helen as somewhat imbecile.
Bees will act like a camel-hair pencil, and it is quite sufficient just to touch the anthers of one flower and then the stigma of another with the same brush to ensure fertilisation; but it must not be supposed that bees would thus produce a multitude of hybrids between distinct species; for if you bring on the same brush a plant's own pollen and pollen from another species, the former will have such a prepotent effect, that it will invariably and completely destroy, as has been shown by Gärtner, any influence from the foreign pollen.
This, at least, is what I gather from Mr. Darwin's provisional theory of Pangenesis; and, again, from one of the concluding sentences in his "Effects of Cross and Self Fertilisation," where, asking the question why two sexes have been developed, he replies that the answer seems to lie "in the great good which is derived from the fusion of two somewhat differentiated individuals.
As the settlers increased they shot down millions of birds of all kinds, and burnt up grass, shrub, and bush. At last, a few years ago, the Government established three islands as "sanctuaries," where many of the more interesting birds survive, and are increasing. Clover depends on bees for its fertilisation and seeding.
The smaller eggs develop without fertilisation, by parthenogenesis, and become males. Here then we have three kinds of gametes, large eggs, small eggs, and sperms, each with the same number of chromosomes. It is not the mere number then which makes the difference, but we find a segregation in the ova into what may for convenience be called female ova and male ova.
Her concern, as we have said, was merely to improve the race by means of crossed fertilisation. To ensure this she has contrived the organ of the male in such a fashion that he can make use of it only in space.
The tadpoles and young frogs so produced are examples of what is called "parthenogenesis" that is to say, virginal reproduction reproduction without fertilisation by material derived from a male parent! The needle, which gives off no material, but simply makes a tiny break in the surface of the egg, does all that is necessary!
Not long ago Jim Hill told the Minneapolis millers that three-fourths of the wheat lands on the American continent were north of the boundary line and that Canada could feed every mouth in Europe. Our wheat crop this year will go nearly 250,000,000 bushels, and this, remember, without fertilisation and with very poor farming, for we Western Canadians are poor farmers.
Only one-seventh of a foot of water, accordingly, could possibly be made available for their fertilisation, supposing them to get the entire advantage of the spring freshet. Upon a stint of less than two inches of water these fertile lands are expected to flourish and bear abundant crops; and since they completely enclose the polar area they are necessarily served first.
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