FAUNAL AREAS 659 



on the same grounds. In such cases, the prevalence of the species of one of 

 the faunae will result in determining the area to which that region belongs. 



It is of the utmost importance to note the fact that these life areas do not 

 regularly blend with one another, but the points of their intergradation 

 may be compared to the meeting of the water and land along the irregular, 

 indented coast of Maine. The irregularity of these life areas and the map- 

 ping out of their various spurs and projections are of the utmost importance 

 to the farmer. By utilizing the northern projections of a more southern 

 fauna he is able to grow its indigenous plants just so much nearer to a 

 northern market, while some dozens of miles to the eastward his neighbor 

 may be utilizing a southward extension of a colder life area to grow boreal 

 plants so much nearer to a southern market. In general the southern 

 extensions of the colder areas will be found along the higher mountain 

 ranges, while the northern branches of the warm areas are in the lowlands 



With these explanations we will proceed to an enumeration of the various 

 primary and secondary areas. The entire world has been divided into eight 

 primary life areas, termed Realms, as follows : 



(1) The Arctic Realm extends across the northern continents, reaching 

 from the northern limit of forest growth to the pole. It is remarkable for 

 the paucity and specific identity of the forms of life occurring throughout it. 



(2) The North Temperate Realm extends from the northern limit of 

 forest growth south to the palm tree belt. 



(3) The American Tropical Realm includes tropical America. 



(4) The Indo-African Realm consists of all Africa, except the northern 

 portion, and tropical Asia with its islands. 



(5) The South American Temperate Realm includes temperate South 

 America. 



(6) The Australian Realm embraces Australia and the islands of 

 Oceanica adjacent thereto. 



(7) The Lemvu-ian Realm is confined to the island of Madagascar. 



(8) The Antarctic Realm occupies the same position in the south as does 

 the Arctic in the north, and the species innabiting it are likewise few and 

 of general distribution. The birds are mainly pelagic. 



All of extreme northern North America is within the Arctic Realm, south 

 of v/hich comes the North Temperate Realm which extends quite to the 

 southern boundary of the United States, except in Florida and Texas where 

 the American Tropical Realm enters the southern portion of these two 

 states. 



Owing to lack of space I will not enter into a discussion of the minor life 

 areas into which each Realm is divided save in the case of such as directly 

 concern Maine. Those wishing more complete information are referred to 

 the following publications : — The Geographical Distribution of North Amer- 

 ican Mammals, J. A. Allen, Bulletin American Museum of Natural History, 

 Vol. 4, pp. 193-243 ; the Geographical and Geological Distribution of North 

 American Mammals ; The Origin and Distribution of North American Birds, 



