ACCLIMATIZE, to accustom an animal or plant to a climate not natural to it. The process, of course, varies widely, according to the amount of difference between the old and the new climate. In cases where the difference is extreme, important changes take place in the constitution, and are often attended with certain diseases described as "diseases of acclimatization." Thus, Europeans settling in tropical parts are liable to disease of the liver, while natives of tropical lands, when resident in England,. are exposed to pulmonary disease. The power of bearing changes of climate is greatest in the Anglo-German race, and usually bears a direct ratio to die intellectuality of a race. Civilized people display greater ingenuity and strength of will than savages in accommo dating themselves to changes of climate, by making careful corresponding changes in their mode of life. 1.71loa and Humboldt assert that persons of and above middle age best stand transportation to tropical climates. Among animals, we find great powers of adaptation to various climates in the horse, dog, cat, rat, etc.; and among plants, in the various cereals, in potatoes, and several weeds common to almost all climates; but there seems to be a limit to the power, at least as seen in the individual. To A. beyond a certain point is the work of some few generations. Almost all the domestic animals now commonly spread over Europe, and even in high northern latitudes, were originally natives of warm climates. The change produced by the acclimatizing of animals may be either an improvement or a deterioration; of the latter, we have an instance in the Shet land pony; of the former, we see an example in the merino sheep of Spain. As an instance of want of the faculty of being acclimatized, the reindeer may serve. Removed from the cold north to the fertile valleys of a temperate clime, the reindeer degenerates and dies. On the other hand, the horse, whose native land is the east, arrives at its
highest development in England; and the Syrian sheep, brought northwards as far as Spain, becomes remarkable for its fine fleece. Spain, on the whole, has a climate much warmer than that of Silesia and Pomerania; and yet the merino sheep. bred in these countries, have become superior to their ancestors imported from Spain. This is a proof that art may do very- much in modifying the influences of climate. Silk-worms, brought from China first into Italy, have been acclimatized not only in the s. of France, but even on the coast of the Baltic. Recently, attempts have been made to A. in France the llama, the vicugna, and the alpaca of Peru, and with some success in the last instance, as alpacas have been found to thrive pretty well in the Pyrenees. It has been very generally believed that plants may become gradually inured to a climate so different from that to which they have been accustomed, that if they had been at once transferred to it, they would have perished. On the other hand:-it is maintained that each species of plant has certain limits of temperature within which it will succeed, and that alleged instances of acclimatizing have been merely instances of plants formerly supposed to be more delicate than they really were. But as it is certain that different varieties of the same species are often more or less hardy, it would seem that in the production of new varieties by seed, there is still a prospect of the acclimatizing. to a certain extent, of species of which the existing varieties are too delicate to grow well in the open air. Of late years numerous acclimatization societies have been formed, the best known being the Paris Sociai d.Acclitnatation.