In sea horses the female has a sort of penis that she uses to inject eggs into the male’s body, neatly reversing the usual method of mating. The eggs develop there, and as the theory predicts, it is the female sea horse who courts the male. There are about thirty species of birds, of which the phalaropes and jacanas are the best-known examples, in which the small dowdy male is courted by the large, aggressive female, and it is the male that broods the eggs and rears the chicks.
