Nearly every group of animals has its giants, its species which tower above their fellows as Goliath of Gath stood head and shoulders above the Philistine hosts; and while some of these are giants only in comparison with their fellows, belonging to families whose members are short of stature, others are sufficiently great to be called giants under any circumstances. Some of these giants live to-day, some have but recently passed away, and some ceased to be long ages before man trod this earth. The most gigantic of mammals--the whales--still survive, and the elephant of to-day suffers but little in comparison with the mammoth of yesterday; the monstrous Dinosaurs, greatest of all reptiles--greatest, in fact, of all animals that have walked the earth--flourished thousands upon thousands of years ago. As for birds, some of the giants among them are still living, some existed long geologic periods ago, and a few have so recently vanished from the scene that their memory still lingers amid the haze of tradition. The best known among these, as well as the most recent in point of time, are the Moas of New Zealand, first brought to notice by the Rev. W. Colenso, later on Bishop of New Zealand, one of the many missionaries to whom Science is under obligations. Early in 1838, Bishop Colenso, while on a missionary visit to the East Cape region, heard from the natives of Waiapu tales of a monstrous bird, called Moa, having the head of a man, that inhabited the mountain-side some eighty miles away. This mighty bird, the last of his race, was said to be attended by two equally huge lizards that kept guard while he slept, and on the approach of man wakened the Moa, who immediately rushed upon the intruders and trampled them to death. None of the Maoris had seen this bird, but they had seen and somewhat irreverently used for making parts of their fishing tackle, bones of its extinct relatives, and these bones they declared to be as large as those of an ox. About the same time another missionary, the Rev. Richard Taylor, found a bone ascribed to the Moa, and met with a very similar tradition among the natives of a near-by district, only, as the foot of the rainbow moves away as we move toward it, in his case the bird was said to dwell in quite a different locality from that given by the natives of East Cape. While, however, the Maoris were certain that the Moa still lived, and to doubt its existence was little short of a crime, no one had actually seen it, and as time went on and the bird still remained unseen by any explorer, hope became doubt and doubt certainty, until it even became a mooted question whether such a bird had existed within the past ten centuries, to say nothing of having lived within the memory of man.