Another South American frog species, named Rhinoderma darwinii after its illustrious discoverer, practises a most unusual version of viviparity. The male appears to eat the eggs that he has fertilised. The eggs don’t travel down his gut, however. Like many male frogs he has a commodious vocal sac, used as a resonator to amplify the voice, and it is in this moist chamber that the eggs lodge. There they develop, until they are finally vomited out as fully formed froglets, forgoing the freedom to swim as tadpoles.
