VOCAL POUCH

in frogs and toads (amphibians of the order Anura), a sac that serves as a resonating chamber. Its opening into the floor of the mouth is partially closed by vocal cords; air forced past the cords into the pouch produces sound by vibrating the cords. Vocal pouches vary greatly in size and shape among species. They may be single or double. Darwin's frog has a distensible vocal pouch in which the male harbours eggs about to hatch until they have hatched and the young can survive outside.