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Updated: May 24, 2025
Whether the hypothesis of Pangenesis be accepted or rejected, it can hardly be doubted that the struggle for existence goes on not merely between distinct organisms, but between the physiological units of which each organism is composed, and that changes in external conditions favour some and hinder others.
II. many bits of hard reading on minute points which we, who have not worked experimentally at cultivation and crossing as you have done, can hardly see the importance of, or their bearing on the general question. If I am asked, I may perhaps write an article on the book for some periodical, and if so shall do what I can to make pangenesis appreciated. I suppose Mrs.
To speak according to pangenesis, the gemmules of hybrids are not injured, for hybrids propagate freely by buds; but their reproductive organs are somehow affected, so that they cannot accumulate the proper gemmules, in nearly the same manner as the reproductive organs of a pure species become affected when exposed to unnatural conditions. This is a very ill-expressed and ill-written letter.
Lastly, in all cases of reversion, characters are transmitted through two, three, or many more generations, and are then developed under certain unknown favourable conditions. This important distinction between transmission and development will be best kept in mind by the aid of the hypothesis of pangenesis.
"Leaving on one side, for the moment, these doubtful and insufficiently investigated cases, we may still maintain that the assumption that changes induced by external conditions in the organism as a whole are communicated to the germ-cells after the manner indicated in Darwin's hypothesis of pangenesis, is wholly unnecessary for the explanation of these phenomena.
The development of such a mode of reproduction by "Natural Selection" seems not less inexplicable than does its continued performance through the aid of "pangenesis." For how can gemmules attach themselves to others to which they do not normally or generally succeed?
Since this theory of Pangenesis has found no adherents, the question may henceforth be restricted to the doctrine of natural selection. This Goette very well observes.
He says, Pangenesis is not to be received because "it leads directly to the negation of a specific vital principle, co-ordinating and regulating all the movements, acts, and functions of the individuals in which it is incarnated. For Pangenesis of the individual is a term without meaning.
This necessitated only verbal alterations; for, though I had not known it, the spirit of the book was throughout teleological. I now saw that I had got my hands full, and abandoned my intention of touching upon "Pangenesis." I took up the words of Mr. Darwin quoted above, to the effect that it would be a serious error to ascribe the greater number of instincts to transmitted habit.
The idea that the relationship of offspring to parent is one of direct descent is, as Galton tells us, "wholly untenable"; and the only reason he admits some supplementary traces of pangenesis into his "Theory of Heredity," is that he may thus account for the more or less questionable cases of the transmission of acquired characters. But there appears to be no necessity even for this concession.
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