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This organ once accepted, the German theory becomes applicable to all the Bees and all the Wasps. When copulating, the female receives the seminal fluid and holds it stored in her receptacle. From that moment, the two procreating elements are present in the mother at one and the same time: the female element, the ovule; and the male element, the spermatozoid.
The pollen of an apple blossom might, for instance, rest upon the stigma of a lily, but the pollen could not penetrate to the lily ovule. It would have no effect upon the lily. That the seed inherits equally from the ovule and the pollen grain is a truth that should be impressed in many ways.
We see that the whole pollen grain could not possibly force its way down to the ovule. It cannot move of itself, for one thing, and if it could it is too large to pass between the tissues of the style.
To understand how the pollen substance finds its way to the ovule substance let us examine the pollen grain a little more carefully. Pollen grains are of many shapes, though usually they are globe-shaped, or football-shaped. Tiny as they are, the outer skin is often marked with grooves and ridges in a very ornamental manner. They have two skins, an outer hard one, a softer inner one.
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. It has also been observed that when the 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.
The cell growth in question is effected in the ovaries; the final stage of the process, the rupture of the containing cell or ovisac, and escape of the ovule, is attended by a concentration of nervous activity in the ganglionic masses sending nerves to those organs analogous to that which occurs in the solar plexus at periods of digestion; the fall of the ovule is itself analogous to the shedding of epithelial cells in the gastric follicles; the afflux of blood to the utero-ovarian veins, analogous to the periodical congestion of the gastro-splenic vascular apparatus.
Careful examination further proves that the whole substance of the nettle is made up of a repetition of such masses of nucleated protoplasm, each contained in a wooden case, which is modified in form, sometimes into a woody fibre, sometimes into a duct or spiral vessel, sometimes into a pollen grain, or an ovule.
A boy is a boy to all intents and purposes from his very conception, from the very earliest moment of his being; begotten by his father he is a boy in embryo within the ovule of his mother. The converse is true of the opposite sex. [A] For fuller particulars see Guernsey's Obstetrics, 3d
But it is the opinion of most physiologists that there is no essential difference between a bud and an ovule in their earliest stages of formation; so that, in fact, "sports" support my view, that variability may be largely attributed to the ovules or pollen, or to both, having been affected by the treatment of the parent prior to the act of conception.
The developing embryo at the end of the suspensor grows out to a varying extent into the forming endosperm, from which by surface absorption it derives good material for growth; at the same time the suspensor plays a direct part as a carrier of nutrition, and may even develop, where perhaps no endosperm is formed, special absorptive "suspensor roots" which invest the developing embryo, or pass out into the body and coats of the ovule, or even into the placenta.
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