Note 290 — Chapter III · THEORY OF THE ORIGINAL PAIRING OR MONOGAMOUS FAMILY
Reading edition
For the social systems among animals, even insects, see Schäffle, Bau und Leben des socialen Körpers, 20 ff.; Wundt, Menschen und Tierseele, 369 ff., 447 ff.; Groos, Spiele der Thiere, 147 ff., 162 ff., 230 ff.; and especially Espinas, op. cit., 207 ff., 274 ff., 458 ff., 543 ff. Compare Houzeau, Étude sur les facultés mentales des animaux; and the other authors on this subject cited in Bibliographical Note III.