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

the group of species hitherto regarded as ant-like, and he adds, 'It is most interesting that Burchell should have noticed the resemblance to an ant in its movements. This suggests that the perfect imitation in shape, as well as in movement, seen in many species was started in forms of an appropriate size and colour by the mimicry of movement alone.' Up to the present time Burchell is the only naturalist who has observed an example which still exhibits this ancestral stage in the evolution of

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

interesting and important of subjects in relation to this theory as well as to evolution. In Mimicry we investigate the effect of environment in its simplest form: we trace the effects of the pattern of a single species upon that of another far removed from it in the scale of classification. When there is reason to believe that the model is an invader from another region and has only recently become an element in the environment  1 More Letters, i. 175. 2 Life and Letters, ii. 245. See also pp

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

of wine.'2 CONCLUSIONS It will probably be convenient to sum up rather fully the chief conclusions contained in the foregoing address.  1. The study of Mimicry possesses special advantages for an understanding of the history and causes of evolution. 1 The letter is addressed: 'The Revd. F. W. Hope, 56, Upper Seymour Street. 'At the head Mr. Hope had written' D', and the date' 1837' . The red-stamped postmark gives the date' Ju. 22, 1837'. Darwin's own address (36, Great Marlborough Street) does

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

far the species of the same genus differ in the ocelli. As I know from your Orchid Drawings how skilful an artist you are, perhaps it would not give you much more trouble to sketch any variable ocelli than to describe them.—I am very much obliged to you for so kindly assisting 1 For a further account of this and other uses of these markings, together with references to the Original memoirs, see' eye-spots' in index of Essays on Evolution (1908), 424. [page] 233 EYE-SPOTS ON BUTTERFLIES' WINGS: 186

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

possible to give the strongest cases opposed to me, and often such conjectures as occur to me.'2 1856, July 19.—'it is absolutely necessary that I should discuss single and double creations, as a very crucial point on the general Origin of species, and I must confess, with the aid of all sorts of visionary hypotheses, a very hostile one.'3 The above-quoted sentences sum up very briefly Darwin's conclusion that evolution as he conceived of it implied that each species had appeared once only in a

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

assistance. The extent of this unintentional, but very serious, misrepresentation of an authority by his exponent, can be most clearly shown by printing together passages by de Vries and Bateson from 1 'Of the inheritance of mutations there is no doubt. Of the transmission of fluctuations there is no very strong evidence. It is therefore reasonable to regard the mutation as the main, if not the only, basis of evolution.'(p. 72.) 2 Mendel's Principles of Heredity, Cambridge (1909), 287. 3 Species

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

hypothesis of the direct influence of environment as a motive cause of evolution:— 'In regard to thorns and spines I suppose that stunted and (illegible) hardened processes were primarily left by the abortion of various appendages, but 1 must believe that their extreme sharpness and hardness is the result of fluctuating variability and the survival of the fittest . 'In a letter to G. H. Lewes, Aug. 7, 1868. More Letters, i. 308.  1 De Vries is here referring to p. 29, where he distinguishes the two

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

'fluctuations' are assumed by him to be transmissible by heredity, and that this assumption is an essential element in the author's definition of his technical term. When we remember that they are just the 'Individual differences' of Darwin, and that de Vries's belief in their powerlessness for continued evolution is based on Francis Galton's well-known law of recession, it is really waste of time to inquire whether they are transmissible. But such positive statements to the contrary have been made by

A36    Periodical contribution:     Darwin Centenary Number. Christ's College Magazine. vol. XXIII, Easter Term, 1909.   Text   Image   PDF

Law that has regulated the Introduction of New Species (Ann. and Mag. Nat. Hist., 1855). The Law is Every species has come into existence coincident both in space and time with a pre-existing closely allied species. Mr Wallace remarks (My Life, Vol. 1. p. 335) This clearly pointed to some kind of evolution but the how was still a secret. Mr Huxley has said of this powerful essay : On reading it afresh I have been astonished to recollect how small was the impression it made. (Life and Letters of

A36    Periodical contribution:     Darwin Centenary Number. Christ's College Magazine. vol. XXIII, Easter Term, 1909.   Text   Image   PDF

of the means by which evolution has taken place in the organic world, the theory of Natural Selection which he published contemporaneously with Mr A. R. Wallace in 1858, and set forth with a wealth of illustration and argument in The Origin of Species in the following year. Now although at the present time we are all evolutionists we hear it frequently said that Darwinism has had its day, and that Natural Selection is insufficient to account for the facts. It is true that very many of the