Several local extinctions of elsewhere existing species are known to naturalists--such as those of the beaver, the bear, and the wolf, which no longer occur in Great Britain, though historically known, as well as organically proved by recent remains, to have lived and died among us. Their extinction was slow and gradual, and resulted entirely from the inroads which the human race--that is, the increase of population, and the progress of agriculture and commerce--necessarily made upon their numbers, which thus became "_few_ by degrees, and beautifully less." The beaver might have carried on business well enough, in his own quiet way, although frequently incommoded by the love of peltry on the part of a hat-wearing people; but it is clear that no man with a small family, and a few respectable farm-servants, could either permit a large and hungry wolf to be continually peeping at midnight through the key-hole of the nursery, or allow a brawny bruin to snuff too frequently under the kitchen door, (after having hugged the watch-dog to death,) when the serving-maids were at supper. The extirpation, then, of at least two of those quondam British species became a work of necessity and mercy, and might have been tolerated even on a Sunday between sermons--especially as naturalists have it still in their power to study the habits of similar wild beasts, by no means yet extinct, in the neighbouring countries of France and Germany. But the death of the Dodo and its kindred is a more affecting fact, as involving the extinction of an entire race, root and branch, and proving that death is a law of the _species_, as well as of the individuals which compose it,--although the life of the one is so much more prolonged than that of the other that we can seldom obtain any positive proof of its extinction, except by the observance of geological eras. Certain other still existing species, well known to naturalists, may be said to be, as it were, just hovering on the brink of destruction. One of the largest and most remarkable of herbivorous animals--a species of wild cattle, the aurochs or European bison (_B. priscus_)--exists now only in the forest of Bialowicksa, from whence the Emperor of Russia has recently transmitted a living pair to the Zoological Society of London. Several kinds of birds are also evidently on their last legs. For example, a singular species of parrot, (_Nestor productus_,) with the termination of the upper mandible much attenuated, peculiar to Phipps's Island, near Norfolk Island, has recently ceased to exist there in the wild state, and is now known as a living species only from a few surviving specimens kept in cages, and which refuse to breed. The burrowing parrot from New Zealand is already on the road to ruin; and more than one species of that singular and wingless bird, called _Apteryx_, also from the last-named island, may be placed in the same category. Even in our own country, if the landed