[45] Gaudry, _Les enchainements du monde animal_, p. 232: Paris, 1878. [46] Hartmann, _Der Gorilla_, pp. 68, 109. [47] _Correspondenzblatt der Deutscher Anthropologischen Gesellschaft_, p. 148, with illustration: 1878. [48] _Zur Morphologie des Gesichtsschädel_, pp. 73, 85, 89: Stuttgart, 1877. [49] Welcker on His und Braune, _Archiv. für Anatomie_, 1881. Rosenberg, Gegenbaur’s _Morphologisches Jahrbuch_, i. 172. [50] _Beiträge zur Geburtshülfe_, p. 161. [51] _Sitzungsberichte der Akademie der Wissenschaften zu Wien_, lxxxv. fig. 1: 1882. [52] Hartmann in _Archiv. für Anatomie_, etc., by Reichert and Du Bois-Reymond, pp. 639–643: 1876. [53] Wiedersheim, _Morphologisches Jahrbuch_, ii. 421. [54] _Archiv. für Anthropologie_, p. 463: 1880. [55] _Alttrojanische Gräber und Schädel. Aus der Abhandlungen der Königl. Akademie der Wissenschaften zu Berlin_, p. 47: 1882. [56] _Sitzungsbericht der Berliner Anthropologischen Gesellschaft_: April 17, 1880. [57] See Spengel’s _Caves and Primitive Inhabitants of Europe_. [58] _Manual of the Anatomy of Vertebrated Animals_, p. 481: London, 1871. [59] _An Introduction to the Osteology of the Mammalia_, p. 310: London, 1870. [60] _On the Anatomy of the Vertebrates_, ii. 551. Also see my own works in _Archiv. für Anatomie_, p. 648: 1876. [61] _Studien aus dem Gebiete du Naturwissenschaften_, ii. 316: St. Petersburg, 1876. [62] Hartmann in _Archiv. für Anatomie_, etc., p. 653: 1876. [63] Welcker in His and Braune’s _Archiv. Jahrg._, i. p. 71. [64] Camper, _Œuvres_, i. 152; _Naturgeschichte des Orang-utan_, etc.; Owen, _Transactions of the Zoological Society of London_, i. 365–368; Ibid., v. 15; Welcker in His and Braune’s _Archiv. Jahrg._, ii. p. 106. [65] _Wiener medicinische Wochenschrift_, p. 4: 1871. [66] Duchenne’s _Mécanisme de la physiognomie humaine_. Darwin’s _Expression of the Emotions_. Gamba’s _Lezioni di anatomo-fisiologia applicata alle arti belle_. [67] Macalister, in the _Annals and Magazine of Natural History_, vii. 342 (1871), asserts that he was unable to distinguish the corrugator from the orbicular muscle, and I have been equally unsuccessful. [68] Darwin’s _Expression of the Emotions_. [69] Darwin, _Expression of the Emotions_. [70] _Proceedings of the Academy of Natural Sciences of Philadelphia_, 1879. _Revue d’Anthropologie_, 1873, 1874. [71] _Proceedings of the Academy of Natural Sciences of Philadelphia_, 1879. [72] Hartmann in _Archiv. für Anatomie_, by Reichart and Du Bois-Reymond, p. 743 (1875); p. 636 (1876). [73] Halford, _Not like man, bimanous and biped, nor yet quadrumanous, but cheiropodus_: Melbourne, 1863. _Lines of demarcation between Man, the Gorilla, and the Macaca_: Melbourne, 1863. I only know these two treatises from Bischoff’s quotation. _Anatomie, etc., des Hylobates leuciscus_, pp. 23, 24. [74] Ruge also considers this muscle to be part of the extensor longus digitorum.