The female elephant

becomes sexually receptive when ten years
old at the youngest, and when fifteen at the oldest; and the male is
sexually capable when five years old, or six. The season for
intercourse is spring. The male allows an interval of three years to
elapse after commerce with a female: and, after it has once
impregnated a female, it has no intercourse with her again. The period
of gestation with the female is two years; and only one young animal
is produced at a time, in other words it is uniparous. And the
embryo is the size of a calf two or three months old.