Outlines of Lessons in Botany; For the Use of Teachers, or Mothers Studying with Their Children (Paperback)

This historic book may have numerous typos and missing text. Purchasers can usually download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1896 edition. Excerpt: ...The ovary is different from any that we have studied. It has four deep lobes (Fig. 27, s), which split apart when the fruit is ripe into four little separate nutlets. But we say that the ovary is syncarpous, for there is only one.style, rising from the centre surrounded by the four lobes. The flower is plainly adapted for cross-fertilization. At the base of the flower, just under the ovary, is a nectar-gland (Fig-27, 8, &). This makes the ovary rather puzzling at first sight, for it looks as if there were five lobes. As 1 Miiller explains this abortion of the stamens by supposing that the plants varied and produced some less conspicuous flowers. As these less attractive flowers would be visited last by insects, and as the stamens of the last-visited plants would be useless, there being no pistillate plants in bloom to be crossfertilized, the stamens would tend to disappear "because the loss of useless organs is manifestly advantageous for every organism."--The Fertilization of Flowers, p. 484. Darwin, on the other hand, supposes that some individuals produced more seed, and consequently less and less pollen, until their stamens finally disappeared. See Forms of Flowers, p. 304. Fig. 27.--Ground-Ivy. 1. Branch with flowers. 2. Base of stem. 3. Flower. 4. Section of same flower. 5. Section of flower in earlier stage. 6. Upper lip, seen from below, the lower lip cut away. 7. Stamen after dehiscence. 8. Ovary: a, nutlets; b, nectar-gland. 9. Fruit, with section of persistent calyx, two ovules fertilized. 10. Diagram. the markings on the flower very plainly show, the path to this nectar-gland leads along the under lip. This brings the head and back of the insect against the four anthers upon the upper lip, and he is dusted with pollen. But in...