ACCLIMATIZATION, the gradual al teration which fits a plant or animal to a climate differing from that in which the habits of its species or race have been formed. Ac climatization and naturalization are often mis takenly used as synonymous, but naturalization properly means establishment in a new country, and, if the climates of the two countries chance to be the same, acclimatization is not implied. In the consideration of marine animals and plants acclimatization takes on a slightly dif ferent meaning, since aquatic life is more affected by the various conditions of the sur rounding water than by climate.
In Plants.— Many examples of acclimatiza tion are furnished by cultivated plants, among which the most noteworthy are perhaps the cereals. The original species of most of these has not been discovered, but in most cases it is supposed to have lived in sub-tropical or warm temperate regions. Some of these cereals now thrive far better or are more productive in cold, northern climates than in warm regions. But in such cases an important influence may to a greater or less extent obliterate or emphasize the apparent of growth, the ness, etc. This is the daily duration of sunlight. During the growing period the sunlight lasts longer as the pole is approached, so that the shorter season is more than compensated for by the increased hours of sunlight. It has been found by experiment that certain varieties of corn brought from the southern States to the northern attained their customary height, but generally failed to ripen seed. The progeny of such plants as did mature seed gradually as sumed the characteristics of northern varieties; they reduced their height and shortened the time necessary to attain maturity. a few they resembled other northern varieties in these two respects. The reverse of this case has also been proved; northern varieties taken to the south at first reached the height and at tained maturity in the time natural to them in the north, but gradually assumed the character istics of southern varieties — increased height and greater number of days to reach maturity.
But even considering the frequent preponder ance of this influence and remembering that the production of seed is usually in opposition to marked development of vegetative parts, there is no doubt that plants, in becoming acclimat ized, are compelled to adjust themselves to many other less prominent influences, such as humidity, temperature, light and wind. The peach is supposed to have come from China by way of Persia, and since early historical times has gradually been fitting itself to more and more northern conditions. It is now found to be a profitabe crop in Michigan and New York, which are several degrees farther north than its supposed place of origin. The influence of cli mate upon cultivated plants is recognized by progressive agriculturists and horticulturists, and each prefers seed grown in a more north erly locality than his own. The effects of the new environment, however, soon become evi dent, and new importations must be made. Seeds grown at high altitudes exhibit the same characteristics as those produced in high lati tudes; that is, they are hardier and require a shorter period to reach maturity than those grown in low altitudes or low latitudes.
Among naturally acclimatized plants are many remarkable phenomena. Deciduous plants taken from cool climates to tropical conditions hold their leaves for a much longer period than where they are indigenous, or may even become evergreen like their new associates. Plants irn. ported from warm regions to cooler may lose the power to ripen seeds, but this defect may be compensated by the development of vegeta tive reproductive powers. The reverse case is also true. Southern plants may fail to ripen wood completely, and winter killing may result. In cultivated plants, however, this phenomenon, which is often observed in the peach, may be due to improper methods of cultivation result ing in abnormal wood-development.