PLANTS OF SOUTHERN NEW JERSEY. 41 



would encircle the globe like the parallels of latitude — the trop- 

 ical zone at the equator, followed by the austral, transition, 

 boreal and arctic as we pass toward the north pole. The inter- 

 vention of a mountain chain, like the Alleghanies, however, run- 

 ning in a general way at right angles to the life zones, materially 

 alters their direction. The higher elevations carry the boreal 

 zone far southward, while the other zones, covering successively 

 lower altitudes, naturally run parallel to the general direction of 

 the mountains. We therefore find (i) that the Boreal zone of 

 Canada and upper Maine is in evidence on the higher mountain 

 tops all the way to western North Carolina, the elevation neces- 

 sary to support it becoming higher and higher as we go south- 

 ward; (2) the Transition (Alleghanian) zone of our northern 

 tier of States, which covers most of New England and New 

 York, spreads southward over all of central Pennsylvania and 

 northern New Jersey, and follows the mountains on both slopes 

 to North Carolina, northern Georgia and eastern Tennessee; (3) 

 the Upper Austral (Carolinian) zone, covering Illinois, Indiana 

 and Ohio, sweeps southward, rounding the lower extremity of 

 the Alleghanies, and then, bending northward again, flanks the 

 Transition all the way to southeastern Pennsylvania and southern 

 New Jersey, sending up terminal arms into the valleys of the 

 Susquehanna, Delaware, Hudson and Connecticut rivers, cover- 

 ing Staten Island and western Long Island, and leaving its trace 

 on the southern coast of New England. Below the Carolinian 

 lies the Lower Austral zone (Austro-riparian), which covers the 

 region between the seashore and a line drawn from the mouth of 

 the Potomac to middle Georgia; thence it bends northward to 

 the juncture of the Ohio and Mississippi, and thence southwest. 

 The Cape Charles peninsula belongs to this zone, and a slight 

 tinge is seen in the plant and bird life of southern Delaware and 

 possibly of extreme southwestern New Jersey. 



Consequently, with the life zones running northeast and south- 

 west, we experience the same sequence of animal and plant life 

 in traveling from the higher Alleghanies of Pennsylvania to the 

 seacoast of southern New Jersey as we do in coming from Maine 

 southward at sea level. 



