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Updated: June 1, 2025
Recent accounts show, that the dust collected from the atmosphere at sea, many miles from land, generally contains some of these dried animalcules and their ova. Many of these germs can be developed only in particular localities, or under certain conditions which are rarely fulfilled.
Nowadays, we see its domain as a limited monarchy, if not indeed as one sovereign state of a republic, a member equal but not superior to the others of a board of directors. Its true business comes down to two particular rôles: first, the production of ova, and, second, the secretion of a hormone or hormones. Over the other functions once supposed its monopoly, all the ductless glands rule.
Internally there were two oviducts, that of the left side normally developed, that of the right diminutive and less than half the full length. The gonad of the left side had the tubular structure of a testis, but showed no signs of active spermatogenesis, but in its lower part contained two ova. Camb. Univ.
After the male has won his bride, he makes a little disc of froth by blowing air and mucus out of his mouth. He then collects the fertilised ova, dropped by the female, in his mouth; and this caused M. Carbonnier much alarm, as he thought that they were going to be devoured.
Those from the male are called sperms or spermatozoa and those from the female eggs or ova. They must join in the process known as fertilization. The chances are half and half that the new individual thus begun will be of a given sex, for the following reason: There is a structural difference, supposed to be fundamentally chemical, between the cells of a female body and those of a male.
Many investigators have found that the Roentgen rays destroy the spermatic cells of the testis in Mammals, leaving the cells of Sertoli, the interstitial tissue, nerves, and vessels uninjured. G. d. Roy. It seems possible, although no such suggestion has been made, that the interstitial cells might either normally or exceptionally give rise to ova and spermatocytes.
There would be no limit to the development of mankind, save the capacities of the planet; and even these, through the skill of man, could be increased a thousand-fold beyond what our ancestors dreamed of. The very seas and lakes, judiciously farmed, would support more people than the earth now maintains. A million fish ova now go to waste where one grows to maturity.
But if the zygote, although compounded of ovum and sperm, is predestined to give rise in the gametes descended from it, either to sperms only or to ova only, it may be suggested that all the somatic cells descended from the zygote are likewise either male or female, although they do not give rise to gametes.
I then tried to impregnate the eggs mechanically, and applied a drop of the spermatic fluid to the egg at the moment of exclusion, and it certainly seemed, in one instance, both to increase the size and to alter the colour of the ova it was applied to; but I was not able to produce the same effect so decidedly in any of my subsequent attempts. P.S. July 27th.
This may cause a temporary sterility, but if persisted in, as is frequently the case in show animals, the sterility becomes permanent because of the genital glands failing to secrete ova and spermatozoa, or the lack of vitality of the male and female elements.
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