THE Scottish National Zoological Park at Edinburgh has long been famous for its penguins—not only for their number and variety and fine condition but also for the manner in which they have bred there. The king penguin bred first in the Park eighteen years ago, and since that time fifteen king penguin chicks have been bred and reared. The ringed penguin and the rockhopper penguin both bred in the Park two years ago. These were the first occasions on which these three species have bred in Britain, and probably the first time they have bred in captivity anywhere. The latest achievement of this kind is the breeding of the gentoo penguin. The gentoo penguin comes next in size to the king penguin. While the king penguin makes no nest but holds its single egg on its feet during incubation, and the rockhopper penguin and ringed penguin make a rough nest of a heap of pebbles, the gentoo penguin prefers something softer, and collects dead grass, twigs and small sticks which it shapes into a symmetrical nest. It was nearly two months after the beginning of the nest building that the first egg was laid, and a second egg was laid five days after the first. Both parents shared in the work of incubation, and took their turns fairly regularly. The first egg hatched after an incubation period of five weeks and four days, but the second was infertile. The chick has a nestling coat of pale grey on the back and white underneath, and it was observed to feed on the day it hatched. It feeds, as do all 'baby' penguins, by taking partially digested fish from the throat of the parent bird.