Apparently, the Creator uses the germ-cell to inaugurate the growth of daughter-cells in the embryo body, in the same manner that a grain of wheat is used to start the growth of a stalk of wheat.
Sec. 19. Reproduction, its Phenomena
All the phenomena of reproduction may be grouped under the following heads: (1) Production of the spermatozoön, (2) production of the ovum, (3) their fusion into the fertilized ovum, (4) production of daughter-cells, (5) distribution, mechanical arrangement and grouping of cells, (6) differentiation of cells into the different tissues, (7) waste of cells.
Sec. 20. Spermatozoön, its Production
The first step toward the reproduction of a man, woman, or any other mammal, (an individual of a species which suckles its young), is the formation of a spermatozoön in the genital organs of a male. See [index], infra, “Spermatozoön.”
Sec. 21. Ovum, its Production
The production of an ovum in the genital organs of a female is the second step. It is immaterial which of them is produced first. The essential point is that they shall meet and fuse into the fertilized ovum.