431 (return) [ Prof. Cope enumerates a number of kinds in his ‘Method of Creation of Organic Types,’ read before the American Phil. Soc., December 15th, 1871, p. 20. Prof. Cope takes the same view as I do of the use of the gestures and sounds made by snakes. I briefly alluded to this subject in the last edition of my ‘Origin of Species.’ Since the passages in the text above have been printed, I have been pleased to find that Mr. Henderson (‘The American Naturalist,’ May, 1872, p. 260) also takes a similar view of the use of the rattle, namely “in preventing an attack from being made.”] 432 (return) [ Mr. des Vœux, in Proc. Zool. Soc. 1871, p. 3.] 433 (return) [ ‘The Sportsman and Naturalist in Canada,’ 1866, p. 53. p. 53.{sic}] 434 (return) [ ‘The Nile Tributaries of Abyssinia,’ 1867, p. 443.] 501 (return) [ ‘The Anatomy of Expression,’ 1844, p. 190.] 502 (return) [ ‘De la Physionomie,’ 1865, pp. 187, 218.] 503 (return) [ ‘The Anatomy of Expression,’ 1844, p. 140.] 504 (return) [ Many particulars are given by Gueldenstädt in his account of the jackal in Nov. Comm. Acad. Sc. Imp. Petrop. 1775, tom. xx. p. 449. See also another excellent account of the manners of this animal and of its play, in ‘Land and Water,’ October, 1869. Lieut. Annesley, R. A., has also communicated to me some particulars with respect to the jackal. I have made many inquiries about wolves and jackals in the Zoological Gardens, and have observed them for myself.] 505 (return) [ ‘Land and Water,’ November 6, 1869.] 506 (return) [ Azara, ‘Quadrupèdes du Paraquay,’ 1801, tom. 1. p. 136.] 507 (return) [ ‘Land and Water,’ 1867, p. 657. See also Azara on the Puma, in the work above quoted.] 508 (return) [ Sir C. Bell, ‘Anatomy of Expression,’ 3rd edit. p. 123. See also p. 126, on horses not breathing through their mouths, with reference to their distended nostrils.] 509 (return) [ ‘Land and Water,’ 1869, p. 152.] 510 (return) [ ‘Natural History of Mammalia,’ 1841, vol. 1. pp. 383, 410.] 511 (return) [ Rengger (‘Sagetheire von Paraquay’, 1830, s. 46) kept these monkeys in confinement for seven years in their native country of Paraguay.] 512 (return) [ Rengger, ibid. s. 46. Humboldt, ‘Personal Narrative, Eng. translat. vol. iv. p. 527.] 513 (return) [ Nat. Hist. of Mammalia, 1841, p. 351.] 514 (return) [ Brehm, ‘Thierleben,’ B. i. s. 84. On baboons striking the ground, s. 61.] 515 (return) [ Brehm remarks (‘Thierleben,’ s. 68) that the eyebrows of the _Inuus ecaudatus_ are frequently moved up and down when the animal is angered.] 516 (return) [ G. Bennett, ‘Wanderings in New South Wales,’ &c. vol. ii. 1834, p. 153. FIG. 18.-Chimpanzee disappointed and sulky. Drawn from life by Mr. Wood.] 517 (return) [ W. L. Martin, Nat. Hist. of Mamm. Animals, 1841, p. 405.]