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It is closely wrapped in the cast skin of the secondary larva, a skin consisting of a diaphanous bag, without any outlet, with running along each side a white tracheal thread which connects the various stigmatic apertures. I easily recognize the seven abdominal stigmata; they are round and diminish slightly in width from front to back. I also detect the thoracic stigma.
For in these older stigmatic flowers the anther as it comes down upon his back is seen to be withered, having shed its pollen several days since, the supply of pollen on the bee's body being sufficient to fertilize all the stigmas in the cluster, until a new supply is obtained from the pollen-bearing blossoms above. And thus he continues his rounds.
Godseff points out to me a reason far more curious and striking. When a bee displaces the pollen masses of a Cattleya, for instance, they cling to its head or thorax by means of a sticky substance attached to the pollen cases; so, on entering the next flower, it presents the pollen outwards to the stigmatic surface.
How strange are these facts! How strange that the pollen and stigmatic surface of the same flower, though placed so close together, as if for the very purpose of self-fertilisation, should in so many cases be mutually useless to each other! How simply are these facts explained on the view of an occasional cross with a distinct individual being advantageous or indispensable!
It has also been observed that when pollen of one species is placed on the stigma of a distantly allied species, though the pollen-tubes protrude, they do not penetrate the stigmatic surface. Again, the male element may reach the female element, but be incapable of causing an embryo to be developed, as seems to have been the case with some of Thuret's experiments on Fuci.
How strange are these facts! How strange that the pollen and stigmatic surface of the same flower, though placed so close together, as if for the very purpose of self-fertilisation, should in so many cases be mutually useless to each other! How simply are these facts explained on the view of an occasional cross with a distinct individual being advantageous or indispensable!
The foot is thus conducted directly between the two viscid discs, which immediately cling closer than a brother, and as the foot is finally withdrawn, the pollen is pulled from its cell. The member now released seeks a fresh hold, and the same result follows, the leg almost inevitably entering the fissure, and this time drawing in the pollen directly against the sticky stigmatic surface within.
And that stigmatic title of long standing, more than anything earthly, drove him to the step-to the ruin of his domestic felicity perhaps. But we are past sighing. 'Think you, when he crossed the tide, Caius Julius Caesar sighed? 'No, nor thought of his life, nor his wife, but of the thing to be done. Laugh, my boy! I know what I am about when I set my mind on a powerful example.
Louis Agassiz was born in Europe, but he was ours by adoption, and he might dispute with Fiske the title to first place in the American Pantheon of Science, were it not for the fact that the Law of Evolution was beyond his ken, being obscured by a marked, myopic, theological, stigmatic squint.
On the other hand, I have found by experiment that the fertility of clover greatly depends on bees visiting and moving parts of the corolla, so as to push the pollen on to the stigmatic surface.
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