The Curator of Reptiles at the San Diego Zoo describes a successful captive breeding programme—after a difficult start—with a highly endangered species. By the beginning of this century the huge daughter of Galapagos tortoises, mostly by sailors in need of fresh meat on board ship, had dangerously reduced their numbers, and the destruction has been continued since by the predators introduced by settlers and visitors—rats, cats, dogs and pigs which preyed on the eggs and young, and goats which competed with the tortoises for food. The first successful hatching of tortoises at San Diego Zoo took place in October, 1958, but fertility is very low, and the author concludes that the tortoises have never reproduced in substantial numbers because, for various reasons, they do not need to do so, and that they are probably incapable of doing so.