[562] Cf. Lönnberg, E., On the Structure of the Musk Ox, P.Z.S., pp. 686–718, 1900.

[563] St Venant, De la torsion des prismes, avec des considérations sur leur flexion, etc., Mém. des Savants Étrangers, Paris, XIV, pp. 233–560, 1856.

[564] This is not difficult to do, with considerable accuracy, if the clay be kept well wetted, or semi-fluid, and the smoothing be done with a large wet brush.

[565] The curves are well shewn in most of Sir V. Brooke’s figures of the various species of Argali, in the paper quoted on p. 614.

[566] Climbing Plants, 1865 (2nd edit. 1875); Power of Movement in Plants, 1880.

[567] Palm, Ueber das Winden der Pflanzen, 1827; von Mohl, Bau und Winden der Ranken, etc., 1827; Dutrochet, Mouvements révolutifs spontanés, C.R. 1843, etc.

[568] Cf. (e.g.) Lepeschkin, Zur Kenntnis des Mechanismus der Variationsbewegungen, Ber. d. d. Bot. Gesellsch. XXVI A, pp. 724–735, 1908; also A. Tröndle, Der Einfluss des Lichtes auf die Permeabilität des Plasmahaut, Jahrb. wiss. Bot. XLVIII, pp. 171–282, 1910.

[569] For an elaborate study of antlers, see Rörig, A., Arch. f. Entw. Mech. X, pp. 525–644, 1900, XI, pp. 65–148, 225–309, 1901; Hoffmann, C., Zur Morphologie der rezenten Hirschen, 75 pp., 23 pls., 1901: also Sir Victor Brooke, On the Clas­si­fi­ca­tion of the Cervidae, P.Z.S., pp. 883–928, 1878. For a discussion of the development of horns and antlers, see Gadow, H., P.Z.S., pp. 206–222, 1902, and works quoted therein.

[570] Cf. Rhumbler, L., Ueber die Abhängigkeit des Geweihwachstums der Hirsche, speziell des Edelhirsches, vom Verlauf der Blutgefässe im Kolbengeweih, Zeitschr. f. Forst. und Jagdwesen, 1911, pp. 295–314.

[571] The fact that in one very small deer, the little South American Coassus, the antler is reduced to a simple short spike, does not preclude the general distinction which I have drawn. In Coassus we have the beginnings of an antler, which has not yet manifested its tendency to expand; and in the many allied species of the American genus Cariacus, we find the expansion manifested in various simple modes of ramification or bifurcation. (Cf. Sir V. Brooke, Clas­si­fi­ca­tion of the Cervidae, p. 897.)