[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] _I^{er} 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.