“Mother love is not a human invention. It has been inherited. It is older than the Rocky Mountains. Mother love in man came from the same source as the backbone in man from pre-human forms. Mother love among men is the same thing exactly as mother love among birds and quadrupeds. The mother monkey loves her child with almost the same tenderness as the human mother. When a monkey child dies, the mother carries the little corpse around with her for clays, refuses to eat, and sits often in silence and grief. Mother birds will risk their very lives for their young. So will mother bears, and lions, and whales, and the females of many other species.”

"Mother Love", p. 61
Savage Survivals (1916), Wild Survivals in Domesticated Animals