[13] As is well known, in an even more notorious example, he proposed to unite Primula vulgaris, P. elatior, and P. acaulis, similarly relying on the existence of "intermediates," which we now well know to be mongrels between the species.
[14] For an account of the distinctions between Vespa vulgaris and germanica see Ch. Janet, Études sur les Fourmis, les Guêpes et les Abeilles, 11e, Note. Sur Vespa germanica et V. vulgaris. Limoges (Ducourtieux), 1895; and R. du Buysson, Monographie des Guêpes, Ann. Soc. Ent. France, 1903, Vol. LXXII, p. 603, Pl. VIII.
[15] The statements made above are for the most part taken from Barrett, C. G., Lepidoptera of the British Islands, and from Tutt, J. W., The British Noctuae and their Varieties. The reader who is unfamiliar with the amazing polymorphism exhibited by some of these moths should if possible take an opportunity of looking over a long series in a collection, or, if that be impossible, refer to the admirable coloured plates published by Barrett. It may not be superfluous to observe that plenty of similar examples are known in other countries. For instance Plotheia frontalis, a Noctuid which often abounds in Ceylon, shows an equally bewildering wealth of forms. If a dozen specimens of such a species were to be brought home from some little known country, each individual would almost certainly be described as the type of a distinct species. (See the coloured plate published by Sir G. Hampson, Cat. Brit. Mus., Heterocera, Vol. IX.)
[16] Dict. of Birds, p. 800. It would be interesting and profitable to attempt in a long series of Ruffs to determine the Mendelian factors which by their combinations give rise to this complex assemblage of varietal forms. A few such factors both of colour and pattern can be at once distinguished, and it is noticeable that some of the resulting types of barring, spangling and penciling show a perceptible correspondence with some of the types of colouration found in the breeds of domestic fowls.
[17] Howard Saunders (Illust. Manual of British Birds, 1899, p. 499) states that there is evidence that the pheasant had become naturalized in the south of England before the Norman invasion. He adds, "little, if any, deviation from the typical P. colchicus took place up to the end of last century, when the introduction of the Chinese Ring-necked P. torquatus commenced, which has left almost indelible marks, especially with regard to the characteristic white collar."
FOOTNOTES: CHAPTER II.
[1] In saying this we make no assumption as to the particular cell-division at which differentiation occurs. This may be one of the maturation-divisions, or it may perhaps be much earlier.
[2] From the recent discoveries of Erwin Baur we are led to surmise that in the flowering plants the sub-epidermal layer, or some of its elements, may legitimately be regarded as a similar germ-substance, continuous in Weismann's sense.
[3] These fraternal twins, which show no special resemblance to each other, are like the multiple births of other animals, and there is no disposition for them to be of the same sex. In the sheep, for example, statistics show that the frequency of pairs of twins, male and female, is approximately double that of the frequency of pairs, both male or both female, as it should be if the sex-distribution were fortuitous. For instance Bernadin (La Bergerie de Rambouillet, 1890, p. 100) gives the following figures for twin-lambs in Merinos: both male, 87; both female, 83; sexes mixed, 187. The 9-banded Armadillo (Dasypus novemcinctus), in which the young born in one litter are said to be always of one sex, is the only known exception in Vertebrates, and is presumably a genuine case of normal polyembryony (see especially, Rosner, Bull. Ac. Soc. Cracovie, 1901, p. 443, and Newman and Patterson, Biol. Bull., XVII, 1909, p. 181), and an important paper lately published by H. H. Newman and J. T. Patterson, Jour. Morph., 1911, XXII, p. 855.