[1] Hermann von Nathusius ‘Die Racen des Schweines,’ Berlin, 1860; and ‘Vorstudien für Geschichte,’ etc., ‘Schweineschädel,’ Berlin, 1864. Rütimeyer, ‘Die Fauna der Pfahlbauten,’ Basel, 1861.
[2] Nathusius, ‘Die Racen des Schweines,’ Berlin, 1860. An excellent appendix is given with references to published and trustworthy drawings of the breeds of each country.
[3] For Europe _see_ Bechstein, ‘Naturgesch. Deutschlands,’ 1801, B. i., s. 505. Several accounts have been published on the fertility of the offspring from wild and tame swine. _See_ Burdach’s ‘Physiology,’ and Godron ‘De l’Espèce,’ tom. i. p. 370. For Africa, ‘Bull. de la Soc. d’Acclimat.’ tom. iv. p. 389. For India, _see_ Nathusius, ‘Schweineschädel,’ s. 148.
[4] Sir W. Elliot, Catalogue of Mammalia, ‘Madras Journal of Lit. and Science,’ vol. x. p. 219.
[6] _See_ J. W. Schütz’ interesting essay, ‘Zur Kenntniss des Torfschweins,’ 1868. This author believes that the Torfschwein is descended from a distinct species, the _S. sennariensis_ of Central Africa.
[7] Stan. Julien quoted by de Blainville, ‘Ostéographie,’ p. 163.
[8] Richardson, ‘Pigs, their Origin,’ etc., p. 26.
[11] Sclater, in ‘Proc. Zoolog. Soc.,’ Feb. 26, 1861.
[12] ‘Proc. Zoolog. Soc.,’ 1862, p. 13. The skull has since been described much more fully by Professor Lucae in a very interesting essay, ‘Der Schädel des Maskenschweines,’ 1870. He confirms the conclusion of von Nathusius on the relationship of this kind of pig.
[13] ‘Journal of Voyages and Travels from 1821 to 1829,’ vol. i. p. 300.
[14] Rev. G. Low ‘Fauna Orcadensis,’ p. 10. _See also_ Dr. Hibbert’s account of the pig of the Shetland Islands.
[16] These woodcuts are copied from engravings given in Mr. S. Sidney’s excellent edition of ‘The Pig,’ by Youatt, 1860. _ See_ pp. 1, 16, 19.
[18] Nathusius, ‘Die Racen des Schweines,’ s. 71.
[19] ‘Die Racen des Schweines,’ s. 47. ‘Schweineschädel’ s. 104. Compare, also, the figures of the old Irish and the improved Irish breeds in Richardson on ‘The Pig,’ 1847.
[20] Quoted by Isid. Geoffroy, ‘Hist. Nat. Gén.,’ tom. iii. p. 441.
[23] ‘Proc. Zoolog. Soc.,’ 1837, p. 23. I have not given the caudal vertebræ, as Mr. Eyton says some might possibly have been lost. I have added together the dorsal and lumbar vertebræ, owing to Prof. Owen’s remarks (‘Journal Linn. Soc.,’ vol. ii. p. 28) on the difference between dorsal and lumbar vertebræ depending only on the development of the ribs. Nevertheless the difference in the number of the ribs in pigs deserves notice. M. Sanson gives the number of lumbar vertebræ in various pigs; ‘Comptes Rendus,’ lxiii. p. 843.
