56 Those who seek information on this point may find it in an interesting tract by Mr. Alexander Bain, on Animal Instinct and Intelligence.
57 The Music of the Most Ancient Nations, &c., by Carl Engel. This quotation is not contained in my essay as originally published, nor in the version of it first reproduced in 1858. Herr Engel’s work was issued in 1864, seven years after the date of the essay.
58 It is far more probable that the ascents and descents made by this gibbon consisted of indefinitely-slurred tones. To suppose that each was a series of definite semi-tones strains belief to breaking point; considering that among human beings the great majority, even of those who have good ears, are unable to go up or down the chromatic scale without being taught to do so. The achievement is one requiring considerable practice; and that such an achievement should be spontaneous on the part of a monkey is incredible.
59 After the above paragraphs had been sent to the printers I received from an American anthropologist, the Rev. Owen Dorsey, some essays containing kindred evidence. Of over three dozen songs and chants of the Omaha, Ponka, and other Indians, in some cases given with music and in other cases without, there are but five which have any reference to amatory feeling; and while in these the expression of amatory feeling comes from women, nothing more than derision of them comes from men.