20 LIFE ZONES AND CROP ZONES. 



ries, blackberries, and cranberries — grow in profusion, and the beech- 

 nut (in the East) is an important food of the native birds and mam- 

 mals. In favored spots, particularly along the southern border, white 

 potatoes, turnips, beets, and the more hardy Russian apples and 

 cereals may be cultivated with moderate success. 



4. THE TRANSITION ZONE. 



The Transition zone (colored blue on the map) is the transconti- 

 nental belt in which Boreal and Austral elements overlap. From 

 New England to the northern Rocky Mountains its course is fairly 

 even and regular, but west of the Great Plains it is tortuous and 

 irregular (see map). The zone as a whole is characterized by com- 

 paratively few distinctive animals and j)lants, but rather by the occur- 

 rence together of southern species which here find their northern 

 limit and northern species which here find their southern limit. It 

 may be subdivided into three faunal areas, which, although grading 

 into one another, are in the main strikingly different: (ft) An eastern 

 humid or Alleglmnian area; (h) a ivestern arid area; (c) a Pacific coast 

 humid area. In the Transition zone we enter from the north the true 

 agricultural part of our country, where many vegetables, the sugar 

 beet, chicory, oats, and numerous varieties of apples, plums, cherries, 

 pears, grapes, white potatoes, and cereals attain their highest perfec- 

 tion. These will be considered more in detail under the subdivisions 

 of the zone. 



{(i) The Alleghanian Faunal Area. 



Tlie eastern humid or AUcijhanian. area comprises tlie greater part 

 of New England, soutlioastern Ontario, New York, Pennsylvania, 

 Micliigaii, Wisconsin, iNIinnesota, eastern Noi-th Dakota, nortlieastern 

 South Dakota, and the Alleghanies from Pennsylvania to Georgia. 

 Its fauna and flora are not homogeneous, but point to an important 

 subdivision west of Lake JVLicliigan, where numerous species occur tluit 

 do not inliabit tlie area east of this lake. A glance at the accompany- 

 ing list of apples, wliere a cross in front of tlie variety indicates its 

 absence from AVisconsin and Minnesota, may be taken as an index to 

 the horticultural importance of this Upper Mississippi subdivision. In 

 the Alleghanian faunal area the chestnut, walnut, oaks, and hickories 

 of the South meet and overlap the beech, birch, liemlock, and sugar 

 nuiple of the North; the Southeni mole and cottontail rabbit meet 

 the Northern star-nosed and Brewer's moles and varying hare, and 

 the Southern bobwhite, Baltimore oriole, bluebird, catbird, chewink, 

 thrasher, and wood thrush live in or near the luiunts of the bobolink, 

 solitary vireo, and the liermit and Wilson's thrushes. Several native 

 nuts, of which the beechnut, butternut, chestnut, hazelnut, hickory 

 nut, and walnut are most important, grow wild in this belt. Of these, 



