[53] Op. cit., p. 22.
[54] Op. cit., p. 215.
[55] “Dürfen wir den Ameisen und Bienen psychische Qualitäten Zuschreiben.” Pflüger’s Archiv., lxx., 1898.
[56] “Solitary Wasps,” p. 219.
[57] Op. cit., pp. 131, 132.
[58] In a letter to Darwin, quoted by Romanes, “Mental Evolution in Animals,” p. 226.
[59] “The Structure and Life of Birds,” p. 335.
[60] Preface to “Harmonia Ruralis,” quoted by Yarrell, “British Birds,” vol. i., p. 541.
[61] American Journal of Psychology, vol. viii., no. 4, pp. 431–493.
[62] “Introduction to Comparative Psychology,” p. 255.