GEOGRAPHICAL DISTRIBUTION. 



The broader facts of the geographical distribution of life are patent 

 to the most casual observer. The primary divisions of distribution, the 

 Tropics, Temperate, and Arctic zones are obvious, but closer study shows 

 that within these broad divisions minor and less obvious ones can be 

 detected. In America, north of the gulf of Mexico, there are three life 

 regions, roughly following the above, called the Tropic, the Austral, and 

 the Boreal. These are subdivided into life zones each characterized 

 by its own peculiar assemblages of plants and animals. 



The Tropic region is sufficiently characterized by name and need be 

 only mentioned. 



The Austral region corresponds roughly to the popular geographical 

 conception of the Temperate zone. It is divided into three life zones, 

 the Lower Austral, the Upper Austral, and the Transition. The Lower 

 Austral might be designated as subtropic and extends north including 

 the gulf of Mexico and the south Atlantic states, but does not reach 

 Canada. The Upper Austral is the first zone in which we are directly 

 interested in eastern Canada, and it merely crosses the border at Lake 

 Erie shore and includes the famous Niagara fruit belt. The frequent or 

 regular occurrence of numerous southern species on Pelee point in Essex 

 county, Ontario, marks the strongest development of this zone in the 

 Dominion. It touches our southern boundary again in Saskatchewan and 

 perhaps includes some of the warmer vallej's running into southern British 

 Columbia. The northernmost Austral or Temperate life zone is the Trans- 

 ition zone, which includes the greater part of the more highly cultivated 

 areas of Canada. It occupies the shores of the bay of Fundy, the upper 

 St. Lawrence river, southern Quebec and Ontario, the lower sections of the 

 prairie provinces, and a strip of sea-coast in southern British Columbia 

 and marks the limit of extensive cultivation. 



The Boreal region is divided into the Canadian, Hudsonian, and the 

 Arctic zones. The Canadian includes the remainder of the forested land 

 north of the Transition and is mostly coniferous, continuing across the 

 continent to the northern limit of general cultivation. The Hudsonian 

 zone is in the more northern country of small shrubs or stunted tree growth 

 unsuited to agriculture, and the Arctic zone extends across the barren 

 grounds north to the pole. 



These life zones based upon temperature and roughly following the 

 lines of latitude, are, however, deflected from their natural east and west 

 sweep by varying local conditions, the vicinity of cold or warm ocean 

 currents, the presence of large bodies of water, elevation above the sea, 

 the prevalence of cold or warm winds, mountain barriers, and other causes. 

 Thus instead of being regular belts they are irregular and only roughly 

 follow parallels of latitude. 



Elevation is an important factor in the distribution of life depending 

 upon temperature. In the tropics in ascending a high mountain, repre- 

 sentatives of each zone between that of the surrounding lowland and the 

 Arctic of the snow-covered peak, may be met with and appropriate assem- 

 blages of species will be found inhabiting each. The meeting of Arctic 

 and Hudsonian zones at the strait of Belle Isle, in the same latitude as 



