The bird-ruled quietude of New Zealand was disturbed 500 years ago by the arrival of the Polynesian Islanders, the Maoris, in their canoes. They brought with them three kinds of vegetables which they cultivated, a dog and a kind of rat. The dogs soon died out, but the rat has remained, and is considered to have done little or no harm. It was not one of the destructive proliferous rats of the northern hemisphere. The Maoris hunted the big birds--the Moas and others--for their flesh, and ate their eggs, and it is probable that they caused or accelerated the extinction of the Moa and two or three other birds. In the north island they nearly exterminated the white heron, the plumes being valued by them. On the whole, very little damage was done to the natural products of the islands by the Maoris. "It was with the advent of the Europeans," says Mr. John Drummond, F.L.S., in his interesting and well-illustrated book on 'The Animals of New Zealand,' "that destruction began in earnest. It seemed as if they had been commanded to destroy the ancient inhabitants." They killed right and left, and, in addition, burnt up the primaeval forests and bushes till a great part of the flora was consumed. It was never a very varied or strong one, consisting only of some 1,400 species, which are now in large proportion vanishing, whilst 600 species of plants, most of them introduced accidentally rather than intentionally by the European settlers, have taken their place. Here I may state the great principle which, in regard to plants as well as animals, determines the survival of intruders from one region to another. It appears that setting aside any very special and peculiar adaptations to quite exceptional conditions in a given area, the living things, whether plants or animals, which are brought to or naturally arrive at such an area, survive and supplant the indigenous plants and animals of that area, if they themselves are kinds (species) produced or formed in a larger or more variegated area; that is to say, formed under severer conditions of competition and of struggle with a larger variety of competitors, enemies and adverse circumstances in general. Thus, the plants of remote oceanic islands are destroyed, and their place and their food are taken by the more hardy "capable" plants of Continental origin. And, in accordance with the same principle, as Darwin especially maintained, the plants of the northern hemisphere, produced as they are in a wide stretching belt of land--Europe, temperate Asia, and North America--always push their way down the great southern stretches of land (by cool mountain roadways), and when they have arrived in the temperate regions of the southern hemisphere, they have at various geological epochs starved out, taken the place of, or literally "supplanted" the native southern flora, which in every case has been formed on a narrow, restricted and peninsula-like area. The same greater "potency" of the animals of the