remnant of the Spitzbergen eiders may be saved when there are so few that it no longer pays to exploit them, but, unfortunately, even this has not saved every persecuted species.
One of the worst destructive features is the intentional introduction of animals to a land to which they are alien. This is usually due to sentiment, but often to a desire, apparently harmless, of improving the fauna by the addition of attractive animals. The result of this well-meaning but mistaken policy is never satisfactory, at any rate for many, very many years. There is no middle course. The introduced creature either finds life so hard in the new land, and enemies so numerous that it dies out at once, or it finds conditions so favourable and natural checks so few that it increases rapidly and some less fitted native succumbs to give it room. Many efforts have been made to improve and increase the variety of our game stock, but whereas the Barbary partridge, the willow grouse, the colin, bob-white, button quail, and even tinamou have been tried and failed, the red-legged partridge has established itself, and the various pheasants have settled down. Amongst mammals the reindeer, wapiti, and beaver rank amongst the failures, the rabbit is perhaps the best instance of a successful colonist; so far has it established itself that we now count it as native, and realise that it has reached that stage when an artificial natural balance with other forms is stable. But can we not guess that awful dislocation of the balance amongst native forms occurred before the rabbit found its level; how many creatures whose absence we mourn may have owed their decline to competition with the rabbit? What it can do when placed in an alien land we know, for is not Australia still faced with the problem? And have not other efforts to check it by introducing its foes—stoat, weasel, dog, cat, and fox—all had bad
