[1] The Wisdom of God manifested in the Works of the Creation, London, 1691.
[2] Ray gives the case of an elephant "that was observed always when he slept to keep his trunk so close to the ground, that nothing but Air could get in between them," and explains it as an adaptation in habit to prevent the mice from crawling into its lungs—"a strange sagacity and Providence in this Animal, or else an admirable instinct."
[3] Trans. Linn. Soc. vol. 23, 1862.
[4] Trans. Linn. Soc. vol. 25, 1866.
[5] Trans. Linn. Soc. vol. 26, 1870.
[6] In attributing this quality to the butterflies in question I am merely stating what is held by the supporters of the mimicry theory. I know of scarcely any evidence either for or against the supposition.
[7] It is assumed that the intelligence of the birds is such that they can learn a pattern after a single disagreeable experience of it.
[8] Untersuchungen über die Mimikry, 1893.
[9] The African mimetic butterflies have been recently monographed by Eltringham in a large and beautifully illustrated work—African Mimetic Butterflies, Oxford, 1910.
[10] Omitting the Hesperidae which hardly enter into questions of mimicry.
[11] The classification adopted is that used by Dr Sharp in the "Cambridge Natural History," Insects, vol. 2, 1901.
[12] Cf. Shelford, Proc. Zool. Soc. 1902.
[13] African Mimetic Butterflies, Oxford, 1910.
[14] These African species of Hypolimnas are frequently referred to the genus Euralia.
[15] Corresponding to the dorippus form of D. chrysippus (cf. Pl. IX) there is a rare form of trophonius known as dorippoides.
[16] These two forms are figured on Plate 10 of Eltringham's African Mimetic Butterflies.
[17] Acraea violae, the only representative of the group in S. India and Ceylon, is nevertheless a very abundant insect. It cannot, however, be said that it is definitely mimicked by any other species in this region.
[18] Coloured figures of these and of the other African species referred to may be found in Eltringham's work on African Mimetic Butterflies.
[19] These descriptions are taken from preserved specimens which I owe for the most part to the kindness of Dr Jordan. I have not had an opportunity of examining fresh ones.
[20] This is more marked in Castnia than in Anthomysa. It appears to be a peculiarity of many members of the genus Castnia that the scales do not lie so tight as generally in moths. Owing to this, some of the large whole-coloured species have a somewhat fluffy look.
[21] Cf. Poulton, Essays on Evolution, 1908, pp. 264-6.
[22] Cf. Poulton, Darwin and the 'Origin,' 1909, pp. 177-186.
[23] The N. American members of this genus are often referred to as Basilarchia.
[24] Darwinism, 1890 (1st Edition 1889), p. 264.
[25] Macrolepidoptera of the World. Fauna Americana, p. 98.
[26] Essays on Evolution, 1908, p. 381.
[27] These "unpalatable" butterflies are sometimes extensively preyed upon by insectivorous birds, when they fall an easier prey owing to their slowness (cf. p. 112).
[28] See Shelford, Proc. Zool. Soc. 1902, p. 260. A coloured figure of both species is given in the paper.
[29] Macrolepidoptera of the World. Fauna Americana, pp. 98-104, Plates 28-30.
[30] "In what way our Leptalis (= Dismorphia) originally acquired the general form and colour of Ithomiae I must leave undiscovered." Trans. Linn. Soc. vol. 23, 1862, p. 513.
[31] Darwinism, 1890, pp. 242-244.
[32] Origin of Species, 6th Edition, 1891, p. 354.
[33] H. misippus was at one time regarded as a clear case of Batesian mimicry. But in view of its plentifulness, of the fact that it may be abundant outside the area inhabited by its model, and of the ease with which it can establish itself in parts remote from its original habitat, e.g. S. America, it has come to be regarded by certain supporters of the mimicry theory as a Müllerian mimic. Cf. Poulton, Essays on Evolution, 1908, pp. 215-217.
[34] An English translation of Müller's paper is given by Meldola, Proc. Ent. Soc., 1879, p. xx.
[35] Trans. Ent. Soc. Lond., 1908, p. 93.
[36] Provided of course that the type form remains in the majority. If the variation occurred simultaneously in more than 50% of A the advantage would naturally be with the variation.
[37] It is possible to imagine an exceptional case though most unlikely that it would occur. Suppose for example that there were a number of distasteful species, say 20, all of different patterns, and suppose that in all of them a particular variation occurred simultaneously; then if the total shewing that variation from among the 20 species were greater than the number of any one of the species, all of the 20 species would come to take on the form of the new variation. In this way it is imaginable that the new pattern would gradually engulf all the old ones.
[38] Trans. Linn. Soc. vol. 24, 1866.
[39] These darker ribs are also present in the male and M female but are obscured owing to the generally deeper colour.
[41] Spolia Zeylanica, 1910.
[42] We shall take it for the present that, from the point of view of mimicry, birds are the main enemies of butterflies (cf. Chap. IX).
[44] The specimens figured on Pl. V were dried in papers when taken. The body is consequently much compressed and the characteristic scarlet of P. hector and P. aristolochiae is largely hidden.
[45] Philosophical Transactions of the Royal Society, vol. 204, 1913.
[46] Tijdschr. voor Entomologie, vol. 53, 1909. A more accessible account is given by de Meijere, Zeit. f. indukt. Abstamm. u. Vererbungslehre, vol. 3, 1910.
[47] For further information see Poulton, Trans. Ent. Soc. Lond. 1909, and various notes in Proc. Ent. Soc. Lond. subsequent to this date.
[48] Science, July, 1908.
[49] If for example there were 5000 dominants and 4000 recessives, and if only half of the population survives to mate, then we should be left with 2500 dominants and 2000 recessives as parents of the next generation. But if there were also a 10% selective disadvantage working against the recessives, their numbers would be further reduced from 2000 to 1800 and the proportion of dominants to recessives would be changed from 5:4 to 25:18.
[50] As these larvae were for the most part found simply over a considerable time it follows that they are the offspring of different females and represent the relative proportions of the three forms in the general population.
[51] The Lepidoptera of Ceylon, 1880.
[52] From the experience of breeders it would appear that the melanic form is somewhat hardier, at any rate in captivity.
[53] Intermediates may also occur in some strains (cf. Bowater, Journal of Genetics, vol. 3, no. 4, 1914).
[54] An interesting case of a similar nature has recently been published by Hasebroek (Die Umschau, 1913, p. 1020). A melanic form of the moth, Cymatophora or, suddenly appeared near Hamburg in 1904. This new form, to which the name albingensis was given, rapidly became the predominant one. In 1911-1912 over 90% of the moths reared from caterpillars taken in the open were of the albingensis form; nor were any intermediates found between it and the typical form. Some experiments were also made which shew that the albingensis form behaves as a dominant to the original type form.
[55] Trans. Ent. Soc. Lond. 1907.
[56] Trans. Ent. Soc. Lond. 1902.
[57] Proc. Zool. Soc. 1911.
[58] Journ. Roy. Asiat. Soc. Bengal, vol. 65, 1897.
[59] Spolia Zeylanica, 1910.
[60] Biological Bulletin, vol. 5, 1903.
[61] Trans. Ent. Soc. Lond. 1909.
[62] Trans. Ent. Soc. Lond. 1902.
[63] Trans. Ent. Soc. Lond. 1911.
[64] Proc. Zool. Soc. 1913.
[65] A Naturalist in Nicaragua, 1874, p. 316.
[66] Ier Congr. Internat, d'Entomologie, Bruxelles, 1911.
[67] Ibis, 1911.
[68] Ibis, 1912.
[69] The Condor, vol. 13, 1911, pp. 195-208.
[70] Journ. Asiat. Soc. Bengal, vol. 64, 1895, and vol. 66, 1897.
[71] Nevertheless a Liothrix is recorded as eating Danais plexippus and a Euploea even though two male specimens of the palatable Elymnias undularis were in the cage.
[72] A form closely resembling P. ceylonica figured on Pl. I, fig. 1.
[73] Proc. Zool. Soc. Lond. 1911.
[74] Proc. Acad. Nat. Sci. Philadelphia, 1912.
[75] C. Hess, Handbuch der vergleichenden Physiologie (herausgegeben von H. Winterstein), Bd. 4, 1912, p. 563.
[76] Journ. As. Soc. Bengal, vol. 662, 1898.
[77] Trans. Ent. Soc. Lond. 1902.
[78] Marshall, loc. cit. p. 379.
[79] In this connection may be quoted a letter from Capt. N. V. Neal near Lagos to Mr W. A. Lamborn which was recently published in the Proceedings of the Entomological Society.
"You have asked me about monkeys eating butterflies. This is very common, as every native will tell you. I have seen it myself. The monkey runs along a path, sees some butterflies fluttering round some filth, goes very quietly, and seizes one by the wings, puts the solid part (body) into his mouth, then pulls the wings off. The poor butterfly goes down like any oyster.... The dog-faced baboon and the large brown monkey with a very long tail, which seems to be the most common species in this colony, are great butterfly-eaters. The little spider-monkey also considers a butterfly a treat, and prefers one to a spider."
[80] Cf. E. B. Poulton in Bedrock for Oct. 1913, p. 301.
[81] Trans. Ent. Soc. London, 1914.
[82] In the female hobleyi, with rare exceptions, the orange of the male is replaced by white, and it has received the name tirikensis. The female of P. macarista also shews white in place of the orange of the male.
[83] Cf. Poulton, E. B., Ier Congr. Internat. d'Entomol., Bruxelles 1911. This proportion is founded on several hundreds caught at random. Observers are agreed that Pseudacraea is both a warier insect and a stronger flyer than the various Planemas which it resembles.
[84] Ier Congr. Internat. d'Entom., Bruxelles 1911.
[85] Cf. Poulton, Bedrock, Oct. 1913, p. 300.
[86] The size of the white spot may shew much variation in specimens from the same region. I have seen African specimens in which it is large, while in the Ceylon specimen figured on Plate IV it is as small as in the typical African specimen shewn on Plate VIII.
[87] See Moulton, J. C., Trans. Ent. Soc. London, 1909.
[88] In this connection it is of interest that a recent observer with considerable breeding experience finds that the dark doubledayaria variety of the Peppered Moth is more hardy than the typical form (cf. p. 101). The swift success of the dark variety led some to regard it as better protected against bird enemies. It is, however, not unlikely that the deeper pigmentation is associated with some physiological difference which makes for greater hardiness. See Bowater, Journal of Genetics, vol. 3, 1914.
[89] As examples may be mentioned P. polytes, Hypolimnas misippus, H. dubius, and Pseudacraea hobleyi. With the exception of the planemoides form it is true also for P. dardanus, the most polymorphic of them all.
[90] Trans. Ent. Soc. Lond. 1909.
[91] Cf. F. G. Hopkins, Phil. Trans. Roy. Soc. 1895.
[92] Coloured representations of these two species will be found on Pl. 20 of Seitz, Macrolepidoptera of the World, Fauna Americana.
[93] Untersuchungen über die Mimikry, 1893.