Did we accept Darwin's provisional hypothesis of pangenesis according to which the parts of the body give off gemmules which are carried as samples to the germ-cells, the possibility of transfer might seem more intelligible.
Darwin's hypothesis of pangenesis as exemplifying the latter view was considered at some length, and the modifications suggested by Professor Brooks, Mr. Galton, and Professor Herdman were indicated.
Only one further modification of pangenesis can here be mentioned, namely, that proposed in 1883 by Professor Herdman, of Liverpool.
Finally, we see that on the hypothesis of pangenesis variability depends on at least two distinct groups of causes.
Anyhow, pangenesis seems to throw a considerable amount of light on the wonderful power of regrowth.
With respect to hybridism, pangenesis agrees well with most of the ascertained facts.
We shall presently see that pangenesis agrees well with the strong tendency to reversion exhibited by all crossed animals and plants.
In the chapter onpangenesis I shall attempt to throw a little light on this fact.
By means of these illustrations the hypothesis of pangenesis has, I hope, been rendered intelligible.
Finally, we can see on the hypothesis of pangenesis that variability depends on at least two distinct groups of causes.
Pangenesis does not throw much light on Hybridism, but agrees well with most of the ascertained facts.
The Graft Theory of Disease, being an application of Mr. Darwin's Hypothesis of Pangenesis to the explanation of the phenomena of the Zymotic Diseases.
It would prove, I think, to demonstration that propagation by buds and by the sexual elements are essentially the same process, as pangenesis in the most solemn manner declares to be the case.
I never received a note from you in my life without pleasure; but whether this will be so after you have read pangenesis (208/1.
Mr. Darwin also does not see the force of the objection to the power of self-division which must be asserted of the gemmules themselves if Pangenesis be true.
Yet it is not at all so, and this fact seems to amount almost to an experimental demonstration that the hypothesis of pangenesis is an insufficient explanation of individual evolution.
This is true; but, on the other hand, let us see whetherPangenesis produces a clearer formula, and one free from unknown elements.
Altogether the hypothesis of Pangenesis seems to be little, if at all, superior to anterior hypotheses of a more or less similar nature.
If then the hypothesis ofpangenesis is well founded, that rite ought to be now absolutely or nearly superfluous from the necessarily continuous absence of certain gemmules through so many centuries and so many generations.
For Pangenesis of the individual is a term without meaning.
Now, though the hypothesis of Pangenesisis no necessary part of "Natural Selection," still any treatise on specific origination would be incomplete if it did not take into consideration this last speculation of Mr. Darwin.
Pangenesis has probably also much truth in it, and has certainly afforded valuable and pregnant suggestions, but unaided and alone it seems inadequate to explain the evolution of the individual organism.
The same may be said with regard to the significant facts of homology, and of organic symmetry; and our consideration of the hypothesis of Pangenesis in Chapter X.
Accordingly I repeated these experiments (with the kind help of Professor Schaefer), but with slight differences in the method, designed to give pangenesis a better chance, so to speak.
The result was his theory of Pangenesis which, ingenious as it was, was ultimately shown to have no basis on fact.
It may be remarked in passing that it is with something of pathos that one reads in Darwin's own works his own evident opinion that this theory of Pangenesis was a great discovery.
This is my case with Pangenesis (which is 26 or 27 years old), but I am inclined to think that if it be admitted as a probable hypothesis it will be a somewhat important step in Biology.
If pangenesis occurs, the transmission of acquired characters ought to be a prominent fact.
Galton restricts the production of gemmules by the personal structure to a few exceptional cases, and would evidently like to dispense with pangenesis altogether, if he could only be sure that acquired characters are never inherited.
Weismann entirely rejects pangenesis and the inheritance of acquired characters.
The gemmules--as in Galton's theory of heredity and with neuter insects--might be perfectly independent of pangenesis and the normal inheritance of acquired characters.
The Darwinian hypothesis ofPangenesis rests on the conception that all inheritable properties are represented in the cells by small invisible particles or gemmules and that these gemmules increase by division.
They are evidently due to the same general conception which prevailed in Darwin's Pangenesis hypothesis.
It is otherwise with Darwin's conception to which Pangenesis owes its name, namely the view that all cells continually give off gemmules, which migrate to other places in the organism, where they unite to form reproductive cells.
But in his Pangenesis hypothesis he has given us the clue for a close study and ultimate elucidation of the subject under discussion.
But in our endeavour to arrive at a true conception of his view I think that the chapter on Pangenesis should be our leading guide, and that we should try to interpret the more difficult passages by that chapter.
This latter is a question which can be solved experimentally; pangenesis was a mental picture present to Darwin's mind, and he threw it out for what it was worth.
Darwin's pangenesis has no value as an hypothesis, it seems to me, apart from its being a pictorial way of illustrating how use and disuse might be inherited.
The chapter on what I callPangenesis will be called a mad dream, and I shall be pretty well satisfied if you think it a dream worth publishing; but at the bottom of my own mind I think it contains a great truth.
I did read Pangenesis the other evening, but even this, my beloved child, as I had fancied, quite disgusted me.
I fear Pangenesis is stillborn; Bates says he has read it twice, and is not sure that he understands it.
What you say about Pangenesis quite satisfies me, and is as much perhaps as any one is justified in saying.
Now these, as far as I can find, are the only grounds for Weismann’s repeated assertion that the theory of pangenesisin any form is “inconceivable.
Professor Weismann still maintains that there is a further important distinction between the theories of pangenesis and germ-plasm, in that the one is pre-formative while the other is epigenetic.
But the theory of pangenesis does not suppose the future organism to exist in the egg-cell as a miniature: it supposes merely that every part of the future organism is represented in the egg-cell by corresponding material particles.
Far from supposing that “all the different cells and tissues of a complex organism must originate de novo from a single reproductive cell,” the theory of pangenesissupposes the very contrary—viz.
Just what the forces at work in this most mysterious of all natural processes are, has been an intellectual mystery that the best minds of the race have attempted to get rid of with words like pangenesis (Darwin).
Together withpangenesis itself, Galton’s theory must be looked upon as preformational, and so far it is in opposition to Weismann’s theory which is epigenetic.
It seems to me, from your epitome of the latter, that if Pangenesis is 'airy,' Perigenesis must be almost vacuous.
Galton was here for a few hours yesterday; I see that he is much less sceptical about Pangenesis than he was.
I only wish I had begun Pangenesis a year earlier, when perhaps by this time the graft-hybrid question might have been settled.
Your letter about Pangenesis made me long for success more even than does the biological importance of the problem.
Pangenesis I always expected would require a good deal of patience, and one year's work on such a subject only counts for apprenticeship.
I confess, however, that but for personal reasons I should have postponed Pangenesis and worked the Medusæ right through in one year.
I am sure it is yours if you do not give up Pangenesis with wicked imprecations.
It was also too late in the year when I began Pangenesis to try the spring flowers, but I hope to do so extensively this winter.
I have an idea that you are afraid I am neglecting Pangenesis for Medusæ.
The theory is ingenious, but seems to sail rather near Pangenesis (as do many of the latter amendments of germ-plasm by W.
The work on Pangenesis and on Medusæ went on through 1876, and some letters to and from Mr. Darwin are here inserted.
You will find pangenesis stiff reading, and I fear will shake your head in disapproval.
Parts of the chapter on Pangenesis I found hard reading, and have not quite mastered yet, and there are also throughout the discussions in Vol.
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 shall be anxious to see howPangenesis is received.
I read the chapter on Pangenesis first, for I could not wait.
The above list will hopefully give you a few useful examples demonstrating the appropriate usage of "pangenesis" in a variety of sentences. We hope that you will now be able to make sentences using this word. Other words: birth; development; generation; parthenogenesis; procreation
