A. Marro, La Puberté, 1901, p. 464.
Lloyd Morgan, Animal Behavior, 1900, pp. 264-5. It may be added that, on the esthetic side, Hirn, in his study (The Origins of Art, 1900), reaches conclusions which likewise, in the main, concord with those of Groos.
It may be noted that the marriage ceremony itself is often of the nature of a courtship, a symbolic courtship, embodying a method of attaining tumescence. As Crawley, who has brought out this point, puts it, "Marriage-rites of union are essentially identical with love charms," and he refers in illustration to the custom of the Australian Arunta, among whom the man or woman by making music on the bull-roarer compels a person of the opposite sex to court him or her, the marriage being thus completed. (E. Crawley, The Mystic Rose, p. 318.)