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The study of the development of the spermatozoon shows that it has come from cells which contained the normal number of four, but that this number has been reduced to one half by a process which is equivalent to that which we have just noticed in the egg. Thus it comes about that each of the sexual elements, the egg and the spermatozoon, now contains one half the normal number of chromosomes.
It had long been known that all higher forms start in life as single cells, egg and spermatozoon. And these, fused in the process of fertilization, form still a single cell.
All organic beings, moreover, include many dormant gemmules derived from their grandparents and more remote progenitors, but not from all their progenitors. These almost infinitely numerous and minute gemmules must be included in each bud, ovule, spermatozoon, and pollen grain."
The ovum then begins to grow, dividing itself into portions that go to make the different parts of the body. Before I continue, let me remind you that the ovum in the beginning is only about as large as the point of a pin, being about 1-125 of an inch in diameter, while the spermatozoon is so tiny it cannot be seen without the aid of a miscroscope.
Provided the requisite conditions for such development are met, these cells are capable of developing into human beings. Each of these remarkable units is called an Ovum, or egg-cell, and represents one variety of the germinal cells. But the other variety, represented by the Spermatozoon and developed only in the male sex, is also required for the production of a human being.
In all probability, at the time of the marital relation, these varieties are deposited in the vagina in equal numbers; and, moreover, the mode of their production is such as to place absolutely beyond human control the possibility of changing this ratio. Since only one spermatozoon enters the ovum, whether or not the child will be a boy or a girl depends entirely upon which type gains entrance.
This is plain from the manner in which the male and female sexual elements unite to form a single ovum, which we observe to be instinct with the memories of both the individuals from which it has been derived; and there is the additional consideration, that each of the elements whose fusion goes to make up the impregnate ovum, is held by some to be itself composed of a fused mass of germs, which stand very much in the same relation to the spermatozoon and ovum, as the living cellular units of which we are composed do to ourselves that is to say, are living independent organisms, which probably have no conception of the existence of the spermatozoon nor of the ovum, more than the spermatozoon or ovum have of theirs.
As the parental nuclei unite, the material which they contain intermingles and establishes a new being; to attain full development, it requires nothing further from the father, and nothing save nourishment from the mother. THE FIRST STEPS IN DEVELOPMENT. Although the identity of the spermatozoon is lost at the moment of fertilization, its influence just then begins to be asserted.
Once I thought he had no suspicion at all. Then he seemed to understand his case as well as I did." "Sarcoma forms like the human embryo," said the younger doctor. "Yes, like the human embryo," the other assented and entered into a long elaboration of this idea. "The germ acts on the cell, as Lancereaux has pointed out, in the same way as a spermatozoon.
There is far more of all these things common to the impregnate ovum and the ovum immediately before impregnation, or again between the impregnate ovum, and both the ovum before impregnation and the spermatozoon which impregnated it.
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