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Updated: June 27, 2025
Others permanently formed of some multiple of four; the highest forms made up of compact, numerous, more or less closely joined cells. Reproduction: by cell division, by the conversion of the cell contents into zoospores, and by resting spores, formed sometimes after conjugation; in other cases, probably, by fecundation by spermatozoids. All the unicellular algae are included under this head.
O. biennis and O. muricata have their stigmas in immediate contact with the anthers within the flower-buds, and as the anthers open in the morning preceding the evening of the display of the petals, fecundation is usually accomplished before the insects are let in. But in O. lamarckiana no such self-fertilization takes place.
STERILITY, IMPOTENCY. Fecundation does not always follow intercourse of the male and female. Impotency in the male and sterility in the female frequently occur. The causes are quite varied. A normal copulation may be impossible because of injuries to, and deformities of, the parts and tumor growths.
Opinion, on the whole, has been opposed to the practice of artificial fecundation, even apart from the question of the probabilities of success. Thus, in France, where there is a considerable literature on the subject, the Paris Medical Faculty, in 1885, after some hesitation, refused Gérard's thesis on the history of artificial fecundation, afterwards published independently.
The Chinese have observed that the last day of menstruation and the two following days corresponding to the period of oestrus constitute the most favorable time for fecundation, and Bossi, of Genoa, has found that the great majority of successes in both natural and artificial fecundation occur at this period.
Dewees quotes two cases, in one of which the child was carried twenty months in the uterus; in the other, the mother was still living two years and five months after fecundation. Another case was in a woman of sixty, who had conceived at twenty-six, and whose fetus was found, partly ossified, in the uterus after death.
Thus cases have been found of women who have been fecundated, and have even arrived at the term of pregnancy, having been obliged to submit to a surgical operation for the removal of the Hymen, which membrane had not been broken in the acts which had nevertheless effected the fecundation.
But when the embryo of the whale still has its teeth in the jaw, the grown up whale its hip-bones, when the eye of man still has its winking membrane, the ear and many portions of the skin their rudimentary muscles of motion, the end of the vertebral column its rudimentary tail, the intestinal canal its blind intestine; when sightless animals, living in the dark, still have their rudimentary eyes, blind worms their shoulder-blades; when in like manner the plants, especially in their parts of fecundation, show in great number such rudimentary organs as are entirely useless for the functions of life, but which are never misleading in determining their relationship with other plants: how simply are all these facts explained by the descent theory, how not at all without it!
Surely this species seeks the water at the time of fecundation, for so do all batrachians, the water being indeed a more fitting medium for fecundation than the air. . .It is certain that the eggs were already fecundated when we found them in the ground, for later, I found several not so far advanced as those you have, and yet after three weeks I had tadpoles from them.
Boussingault remarks: "In many flowers there has been observed a very considerable evolution of heat, at the approach of fecundation. If we suppose the fecundation of the flowers of forest trees to be attended with a tenth only of this calorific power, they could not fail to exert an important influence on the warmth of the atmospheric strata in contact with them.
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