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Show r CHAPTER IV ANIMAL LIFE OP NORTH AMERICA ( 1500- 1900) ANY general discussion of the continent in its i\ relation to history must include a description of its fauna so far as it has affected the settlement of the country. From the stand- point of human interest the vertebrates are immeasurably more significant than any other forms of animal life; but it will be necessary to select those vertebrates which are indigenous, neglecting such as have been introduced by Europeans, such as the domesticated animals and the domestic animals run wild, as broncos, mustangs, and cattle of the western plains. The insects might also be considered of importance to man because of their destructive relations to agriculture and forestry. \ Almost any given animal inhabits a more or less restricted geographic area, known as its " range," the limits of which are determined by climatic conditions ( temperature and moisture) or by the interrelation of land areas, since intervening bodies of water serve as barriers to the dispersal of the species. Of these two factors temperature is vastly .54 |