Accli'matiza'tion or Ac'clima'tion, the process by which a plant or animal adapts itself to a climate which is not natural to it. If the new species establishes itself in the new climate, the process is called naturalization. Cultivated plants, such as cereals, the potato and common fruits, are the best examples of acclimatization. Although in most of these the process seems to have been perfected, yet certain limitations are always appearing; for instance, corn cannot be grown in the short, cool seasons of the northern temperate regions, while wheat does not thrive as well in the warmer climates. There are countless instances of partial acclimatization, where the plant may grow thriftily for a time but fail to mature fruit or to reach the same woody structure which it possesses in its natural home. Animals vary considerably in their power to adapt themselves to different climates. Some, such as the dog, the cat, the domestic fowls and mice, have followed man into all parts of the world and seem to thrive wherever they locate. In general, it is true that any animal organism may adapt itself perfectly to certain conditions if they are presented slowly and by degrees, while if thrown suddenly among the same conditions it will die. Man himself possesses great adaptability, yet when changes are made suddenly, he may fall prey to fatal diseases. Whenever representatives of the races inhabiting the temperate climates are transported to the tropics, they find it difficult to preserve health and vigor for any great length of time. Modern sanitation and intelligent care, however, enable these people to live for many years in hot climates, preserve their health and even carry on the industries of their first home. Ripley's Racial Geography of Europe, Heilprin's Geographical and Geological Distribution of Animals and Ireland's Tropical Colonization are standard works of reference on this subject.