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A331    Book:     Poulton, Edward Bagnall. 1909. Charles Darwin and the Origin of species: addresses, etc., in America and England in the year of the two anniversaries. London: Longmans, Green, and Co.   Text   Image
through a crowded area without producing any effect on any member of the Lepidopterous fauna, or without themselves being affected thereby.'1 Abundant wide-ranging Danaines in the Old World, even when much smaller and with a less marked appearance, invariably produce some effect, and often themselves exhibit Müllerian resemblances. THE EVOLUTION OF LIMENITIS (BASILARCHIA) ARCHIPPUS AS A MIMIC OF THE INVADING DANAIDA PLEXIPPUS It has already been mentioned that a single species, undergoing
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A331    Book:     Poulton, Edward Bagnall. 1909. Charles Darwin and the Origin of species: addresses, etc., in America and England in the year of the two anniversaries. London: Longmans, Green, and Co.   Text   Image
between such specimens and those from Florida, and also to ascertain the proportion which they bear to typical archippus. By far the most important feature in the evolution of floridensis is the general darkening of the ground-colour, and the material for such a transformation certainly exists freely in archippus, for the shade of brown varies immensely and may often be seen of as dark a tint as in floridensis, but not in my experience of precisely the same shade. [page] 171 INVESTIGATIONS
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A331    Book:     Poulton, Edward Bagnall. 1909. Charles Darwin and the Origin of species: addresses, etc., in America and England in the year of the two anniversaries. London: Longmans, Green, and Co.   Text   Image
that later, after the separation had become complete, it spread northward over the whole range of its parent. The evolution of astyanax from arthemis was far simpler than that of archippus. The great difference in appearance between parent and offspring is brought about, as regards the upper surface, by the disappearance of the broad white band of arthemis together with all but a trace of the sub-apical white markings of the fore wings. Over and within the area formerly occupied by the white
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A331    Book:     Poulton, Edward Bagnall. 1909. Charles Darwin and the Origin of species: addresses, etc., in America and England in the year of the two anniversaries. London: Longmans, Green, and Co.   Text   Image
a set of dark female forms well known in Argynnis, forms which he believes to be ancestral.1 It is probable that' the recent evolution of L. astyanax provided this ancestral form with a model which it could approach by small and easy steps of variation'.2 THE BEARING UPON THEORIES OF MIMICRY OF PHARM. PHILENOR AND ITS MIMICS Haase, who always shows an imperfect appreciation of the scopo of Fritz Müller's principle, apparently regarded all the species mentioned in the preceding section as simple
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A331    Book:     Poulton, Edward Bagnall. 1909. Charles Darwin and the Origin of species: addresses, etc., in America and England in the year of the two anniversaries. London: Longmans, Green, and Co.   Text   Image
profound significance still, for the comprehension of the method of evolution, is the vast performance of Nature herself.1 Because of the bright promise it holds for the understanding of Nature's experiments, I have brought before you the subject of Mimicry in North American butterflies. In the introductory words I spoke of the relationship of my subject to the teachings of Darwin, and now I am anxious to connect this address by a closer link to the personality of the illustrious naturalist. With
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A331    Book:     Poulton, Edward Bagnall. 1909. Charles Darwin and the Origin of species: addresses, etc., in America and England in the year of the two anniversaries. London: Longmans, Green, and Co.   Text   Image
conclusion that the Mimicry is in an incipient stage and that it has been reached and is probably still advancing by minute increments,—that the evolution is 'continuous'tothe last degree. 32. In addition to their bearing upon the problems of Mimicry, the examples considered 1 In the southernmost part of the range of bredowi, in Guatemala, the resemblance to Adelpha was very slightly augmented in the only two specimens from this locality I have had the opportunity of studying (Trans. Ent. Soc. Lond
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A331    Book:     Poulton, Edward Bagnall. 1909. Charles Darwin and the Origin of species: addresses, etc., in America and England in the year of the two anniversaries. London: Longmans, Green, and Co.   Text   Image
endangered by the one man who held the same belief on much stronger grounds. We find the great geologist, at a later stage, ready to give up his belief if he can thereby obtain a weapon against evolution; and observe, in Darwin's answer to him and to the Duke of Argyll, an entire grasp of the problem conspicuously wanting in those authorities who expressed, at a—later date, an ill-founded enthusiasm for the worthless hypothesis of multiple Origins. [page] 25
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A36    Periodical contribution:     Darwin Centenary Number. Christ's College Magazine. vol. XXIII, Easter Term, 1909.   Text   Image   PDF
world in the Beagle. Is there any one now in College of whom a freshman of 1908 9 will write in a like strain, sixty years hence? JOHN PEILE. DARWIN AND THE LINNEAN SOCIETY. AT a special meeting of the Linnean Society of London held on the 1st of July, 1908, to celebrate the fiftieth anniversary of the reading of the joint papers on evolution by Charles Robert Darwin and Alfred Russel Wallace, the following striking words were spoken by Mr Francis Darwin: I wish to say a few words in my private
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A36    Periodical contribution:     Darwin Centenary Number. Christ's College Magazine. vol. XXIII, Easter Term, 1909.   Text   Image   PDF
about that organic diversity which has found such endless expression. But however this may be, it will ever stand to Darwin's credit that he did more than any other man to extend to the field of biology that great unifying principle of evolution, the recognition of which made it possible for an English bishop to write, All that lives, lives with one life. If we know that we share in this, we can wait for the revelation of its action. F. H. A. MARSHALL. [page] 24
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McGill-CA-OSLER0-P110[.166]    Note:    [1909]   4pp list of items to display at Darwin exhibition, Christ's College, Cambridge   Text   Image
The Complete Work of Charles Darwin Online 1 (✓ = sent now June 4) s ✓ 1 MSS First sketch of Origin of Species 1842 2 Second Sketch ─ 1844 s ✓ 3 s ✓ Note Book — a 'Beagle voyage 4 books ✓ s ✓ b Books to be Read 2 s ✓ - c Earliest Notes on Evolution B 1837 (1) s ✓ 4 Notes on Paley's Evidence s ✓ 5 ✓ Notes on Geology 2 envelopes s ✓ 6 ✓ Page of Expression of the Emotions 7 Zoological Note Book 1837? s ✓ 8 ✓ Diary- to 1881 s ✓ 9 Lecture tickets — Edinburgh University 2 lots ✓ s ✓ 10 Calling over
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A162    Book:     Seward, A. C. ed. 1909. Darwin and modern science. Essays in commemoration of the centenary of the birth of Charles Darwin and of the fiftieth anniversary of the publication of The origin of species. Cambridge: Cambridge University Press.   Text   Image   PDF
was not less fundamental,—it was the idea of the correlation of organisms. This, again, was not novel; we find it in the works of naturalist like Christian Conrad Sprengel, Gilbert White, and Alexander von Humboldt, but the realisation of its full import was distinctively Darwinian. As Regards the General Idea of Organic Evolution. While it is true, as Prof. H. F. Osborn puts it, that 'Before and after Darwin' will always be the ante et post urbem conditam of biological history, it is also true
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A162    Book:     Seward, A. C. ed. 1909. Darwin and modern science. Essays in commemoration of the centenary of the birth of Charles Darwin and of the fiftieth anniversary of the publication of The origin of species. Cambridge: Cambridge University Press.   Text   Image   PDF
the mutability of species, and he was far ahead of his age in his suggestion of what we now call a Station of Experimental Evolution. Leibnitz discusses in so many words how the species of animals may be changed and how intermediate species may once have linked those that now seem discontinuous. All natural orders of beings present but a single chain ... All advances by degrees in Nature, and nothing by leaps. Similar evolutionist statements are to be found in the works of the other
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A162    Book:     Seward, A. C. ed. 1909. Darwin and modern science. Essays in commemoration of the centenary of the birth of Charles Darwin and of the fiftieth anniversary of the publication of The origin of species. Cambridge: Cambridge University Press.   Text   Image   PDF
Selection in his exposition of the eliminative processes which go on in mankind, the suggestive value of his essay is undeniable, as is strikingly borne out by the fact that it gave to Alfred Russel Wallace also the long-sought clue to the effective agent in the evolution of organic species1. One day in Ternate when he was resting between fits of fever, something brought to his recollection the work of Malthus which he had read twelve years before. I thought of his clear exposition of 'the
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A162    Book:     Seward, A. C. ed. 1909. Darwin and modern science. Essays in commemoration of the centenary of the birth of Charles Darwin and of the fiftieth anniversary of the publication of The origin of species. Cambridge: Cambridge University Press.   Text   Image   PDF
success attended his application of the Selection-formula that for a time he regarded Natural Selection as almost the sole factor in evolution, variations being pre-supposed; gradually, however, he came to recognise that there was some validity in the factors which had been emphasized by Lamarck and by Buffon, and in his well-known summing up in the sixth edition of the Origin he says of the transformation of species: This has been effected chiefly through the natural selection of numerous successive
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A162    Book:     Seward, A. C. ed. 1909. Darwin and modern science. Essays in commemoration of the centenary of the birth of Charles Darwin and of the fiftieth anniversary of the publication of The origin of species. Cambridge: Cambridge University Press.   Text   Image   PDF
in which all the conditions of life to which they were adapted occurred: the humming-birds at the same time as the flowers; the trichina at the same time as the pig; the bark-coloured moth at the same time as the oak, and the wasp-like moth at the same time as the wasp which protects it. Without processes of selection we should be obliged to assume a pre-established harmony after the famous Leibnitzian model, by means of which the clock of the evolution of organisms is so regulated as to strike
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A162    Book:     Seward, A. C. ed. 1909. Darwin and modern science. Essays in commemoration of the centenary of the birth of Charles Darwin and of the fiftieth anniversary of the publication of The origin of species. Cambridge: Cambridge University Press.   Text   Image   PDF
scales were scattered over the surface of the wing, but gradually they concentrated themselves, and formed broad, velvety bands, or strong, prominent brushes, and they attained their highest pitch of evolution when they became enclosed within pits or folds of the skin, which could be opened to let the delicious fragrance stream forth suddenly towards the female. Thus in this case also we see that characters, the original use of which was to bring the sexes together, and so to maintain the species
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A162    Book:     Seward, A. C. ed. 1909. Darwin and modern science. Essays in commemoration of the centenary of the birth of Charles Darwin and of the fiftieth anniversary of the publication of The origin of species. Cambridge: Cambridge University Press.   Text   Image   PDF
useless. On the other hand, he strongly combated the belief, that great changes would be necessary to explain the origin of species. Some authors had propounded the idea that highly adapted organs, e.g. the wings of a bird, could not have been developed in any other way than by a comparatively sudden modification of a well defined and important kind. Such a conception would allow of great breaks or discontinuity in the evolution of highly differentiated animals and plants, shortening the time
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A162    Book:     Seward, A. C. ed. 1909. Darwin and modern science. Essays in commemoration of the centenary of the birth of Charles Darwin and of the fiftieth anniversary of the publication of The origin of species. Cambridge: Cambridge University Press.   Text   Image   PDF
guessed at by him. 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. A careful and often repeated study of the Pangenesis hypothesis has convinced me that Darwin, when he wrote that chapter, was well aware that ordinary variability has nothing to do with evolution, but that other kinds of variation were necessary. In some chapters he comes
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A162    Book:     Seward, A. C. ed. 1909. Darwin and modern science. Essays in commemoration of the centenary of the birth of Charles Darwin and of the fiftieth anniversary of the publication of The origin of species. Cambridge: Cambridge University Press.   Text   Image   PDF
condition was in the main the result of Selection, with disuse aiding, and in another place that the main cause of degeneration was disuse, but that Selection had aided. To Darwin however I think the point would have seemed one of dialectics merely. To him the one paramount purpose was to show that somehow an Evolution by means of Variation and Heredity might have brought about the facts observed, and whether they had come to pass in the one way or the other was a matter of subordinate concern
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A162    Book:     Seward, A. C. ed. 1909. Darwin and modern science. Essays in commemoration of the centenary of the birth of Charles Darwin and of the fiftieth anniversary of the publication of The origin of species. Cambridge: Cambridge University Press.   Text   Image   PDF
hypotheses have been formulated on these lines, with special reference to the evolution of man. Pithecanthropus is regarded by some authorities as the direct ancestor of man, by others as a side-track failure in the attempt at the evolution of man. The problem of the monophyletic or polyphyletic origin of the human race has also been much discussed. Sergi2 inclines towards the assumption of a polyphyletic origin of the three main races of man, the African primitive form of which has given rise
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