Page:Popular Science Monthly Volume 33.djvu/752

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732
THE POPULAR SCIENCE MONTHLY.

Arabs of the desert, and one of which now waves its long boughs in the breeze before us, are all female; the male or pollen-bearing flowers of the date kind always grow on a separate tree; and as pollen is produced by them in vast quantities, it is not necessary in palm-groves to have more than a single male stem to some forty or fifty fruit-bearing individuals. The Arabs, therefore, never raise their palms from seed, as they can not make sure of the sex of seedlings; they take suckers from the root of a female tree, already known to be a good bearer of fine fruit; and these suckers not only follow the sex of the so-called mother, but also reproduce its special peculiarities of flower and seed in every respect. They can not fail to do so, indeed, seeing that they are part and parcel of the original palm, actual members of the self-same plant; just as the various branches of an apple-tree all bear the same kind of apples, or the boughs of a currant-bush all produce the self-same currants.

And now let us hark back, by way of contrast, to the case of the pea, which is a true, distinct, individual plant, the product of a veritable marriage union. Whence came it? Was it born from a pea-blossom? So, indeed, we mostly imagine; though very incorrectly. As well say that a child is the son of his mother, but not of his father, as that a pea is the seed produced by a pea flower. It is nothing of the sort. The whole secret of sex and reproduction is bound up in this simple illustrative instance. The pea is the product of two different pea-blossoms.

The mere accidental fact that each pea-blossom had stamens and pistil in its own flower must not blind us to the truth of this underlying principle of cross-fertilization, which every pea exemplifies for us as truly as every date or every melon. In the date and the melon the flowers on one plant are all male or all female; on the pea-vine they are all hermaphrodite. But, none the less, they intermarry. What happened when the pea was first launched into life was briefly this: A row of peas grew in the garden of the Moorish villa that gleams in the sun on the hill-side opposite; and on one of these vines hung a particular white-winged blossom, which supplied the pollen for the production of this individual pea. On another vine hung a second flower, from whose midst protruded the pistil which was finally to grow out into the particular pod that contained my pea. A wandering bumble-bee, on dinner intent, poked his long proboscis into pea-flower number one, and, after rifling it of its honey, covered his hairy legs and thighs, half accidentally, with abundant pollen from the stamens, which formed a sheath or tube round its twisted style. Then he flew away to pea-flower number two, and, in his clumsy attempts to thrust his long sucker down its nectar-bearing throat, he brushed a lot of number one's pollen from his legs and breast on