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Updated: May 10, 2025
Thus by a use of carefully chosen, well-understood terms the child has from the very beginning a dawning sense of the oneness of all life. He can be told that "ovule" means little egg, and that the seed of the plant is the egg of the plant, which hatches sprouts into the plant we see. It is better not to break the tender little pod to show the ovules, even if there are plenty of flowers.
We then have a little box full of ripe pollen grains. The pollen grain is like the ovule in structure, only much smaller. It is so tiny and the anther so small that we cannot watch its development as we can that of the ovule. But botanists have taken great pains to examine the pollen and to watch its development under the microscope, so that from them we know the truth.
"The same experiment can be tried with the embryos of animals. Take the ovule of the worm, the eagle, the elephant, and of man himself. Let the most skilled observer apply the most searching tests to distinguish the one from the other, and he will fail. "But there is something more surprising still.
The result of this act on the part of the male and female is, that the formation of a new being is set up in the ovule or egg; this ovule or egg soon begins to be divided and subdivided, and to be fashioned into various complex organisms, and eventually to develop into the form of one of its parents, as I explained in the first lecture.
In other words, the seed inherits from the pollen as well as from the ovule. Inheritance is a very wonderful thing. It is that power which causes the offspring to resemble its parents.
Sexual reproduction is quite a distinct matter. Here, in all these cases, what is required is the detachment of two portions of the parental organisms, which portions we know as the egg or the spermatozoon. In plants it is the ovule and the pollen-grain, as in the flowering plants, or the ovule and the antherozooid, as in the flowerless.
In either case the essential points are a clear understanding of the growth of the ovule in the ovary, the manner in which it is nourished and protected, and its final separation from the ovary to enter into the outer world as an individual provided with everything necessary to its needs.
Even in first crosses, the greater or lesser difficulty in effecting a union apparently depends on several distinct causes. There must sometimes be a physical impossibility in the male element reaching the ovule, as would be the case with a plant having a pistil too long for the pollen-tubes to reach the ovarium.
There are two ovaries, with their oviducts, in the young bird, but these are so small that it is very difficult indeed to find them. As the bird approaches maturity, one ovary and its oviduct enlarge, and the ova, which develop from the inside of the ovary just as the ovule develops inside the flower ovary, also become large.
Hind-brain, cerebellum, medulla oblongata. d. Eye. e. Ear. f. First visceral arch. g. Second visceral arch. H. Vertebral columns and muscles in process of development. i. Anterior extremities. K. Posterior extremities. Man is developed from an ovule, about the 125th of an inch in diameter, which differs in no respect from the ovules of other animals.
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