“Most flowers have both stamens and pistils. All those we have just looked at are in that class. But there are plants that have some flowers with stamens and others with pistils. Sometimes the flowers with stamens only and those with pistils only are found on the same plant; sometimes they are found on separate plants. “Did I not fear to overcharge your memory, I would tell you that plants having flowers with stamens only and flowers with pistils only on the same plant are called monœcious plants. This expression means ‘living in one house.’ In a word, the flowers with stamens and those with pistils live together in the same house, since they are found on the same plant. The pumpkin, cucumber, melon, are monœcious plants. “Vegetables whose flowers with stamens and flowers with pistils are found on different plants are termed diœcious; that is to say, plants with a double house. By this is meant that the ovary and pollen are not found in the same plant. The locust, date, and hemp are diœcious. [Illustration: Flowering branch of Locust Tree] “The locust is a tree of extreme southern France. Its fruit grows in pods similar to those of the pea, but brown, very long, and plump. This fruit, in addition to seeds, has a sugary flesh. Supposing we took a notion, if the climate permitted, to grow locust seeds in our garden. What locust tree must we plant? Evidently the tree with pistils, because it alone possesses the ovaries which become fruit. But that is not enough. Planted by itself, the locust tree with pistils will be able to blossom abundantly every year, without ever producing any fruit; for its flowers would fall without leaving a single ovary on the branches. What is wanting? The action of the pollen. Close to the locust with pistils let us plant one with stamens. Now fructification proceeds as we wish. Wind and insects carry the pollen from the stamens to the stigmas; the torpid ovaries spring to life, and in time the locust pods grow and ripen perfectly. With pollen, fruit; without pollen, no fruit. Are you convinced, Jules?” “Without doubt, Uncle; only, unfortunately, we do not know the locust. I should prefer a plant of our own region.” [Illustration: Date-palm] “I will tell you of one that will permit you to prove what I have told you; but first of all let me mention a second example. “The date-tree, like the locust, is diœcious. Arabs cultivate it for its fruit,—dates, their chief food.” “Dates are those long fruits of a very sweet taste, preserved dry in boxes,” said Jules. “A Turk was selling some at the last fair. The kernel is long and split all along one side from one end to the other.”