Animal Aggregations.

DEEGENER'S great work “Die Formen der Vergesellschaftung im Tierreiche”, 1918, was completely spoilt for us by its cumbrous classification of animal aggregations and the impossibility of assigning many cases to any single group. He saw that many animals normally live in communities consisting of a single or a few species, and was inclined to regard this as a general phenomenon. Earlier, Espinas, in 1878, had developed similar views. “Communal life, therefore, is not an accidental fact in the animal kingdom; it does not arise here and there fortuitously, and, as it were, capriciously . . . but . . . a normal, constant, universal fact.” Wheeler, in 1930, classified aggregations into loosely integrated associations and more permanent societies. The extreme cases of the latter are in ants, termites and bees, and in man. These are not comparable, but Wheeler has shown more than thirty cases of prolonged association of young and adults in five orders of insects. In most cases it is an association of mother and offspring, the chief bond being ‘trophallaxis’ or mutual feeding. This family basis accounts for much of the phenomena of flocks, herds, and uman societies, a certain amount of recruiting from outside being allowed.Animal Aggregations: a Study in General Sociology.By W. C. Allee. Pp. ix + 431. (Chicago: University of Chicago Press; London: Cambridge University Press, 1931.) 22s. 6d. net.