FREE INSTITUTE OF SCIENCE 



THE LIFE FEATURES OF THE COASTAL PLAIN AND THE PIEDMONT 



tion to the variety of surface conditions — forest, grassland, desert and scrub, 

 swamp, jungle, and river shore. Each one of these fundamentally vegetational 

 differences constitutes a "habitat" for some group of creatures. The fauna 

 of a region is thus the sum of as many local or habitat faunas as exist within the 

 region itself. The regional fauna is, in the main, a geographic problem; 

 the local, habitat fauna is a problem in ecology. This relationship to par- 

 ticular tracts of country on the part of any species of animal is a part of the 

 species' history and in most cases is of considerable antiquity. Both of the 

 above-mentioned birds belong to the CaroHnian fauna, so far as their regional 

 association is concerned, but the Prairie Warbler is a "pine barren "type, while 

 the Worm-eating Warbler's ecologic affinities are with the hardwood growth 

 of the interior forest. 



It must be already quite clear that in the Philadelphia district we are sur- 

 rounded by the remnant of this great southern interior hardwood forest on its 

 northeastern fringe, and that, near at hand, just across the Delaware in New 

 Jersey, are the "pines" — the northern frontier of that vast pine woodland of 

 the South Atlantic Coastal Plain. In colonial days a Hne run by the English 

 surveyors, Mason and Dixon, arbitrarily fixed a boundary that in after-years 

 made a "North" and a "South." The real physical and biological "South," 

 however, as we now know it, reaches to the fall-line of the lower Delaware, and 

 the city of Philadelphia touches the edge of "Dixie-land." One with an eye 

 for the countryside realizes this — the clear whistle of the Cardinal and the loud 

 chant of the Carolina wren betoken it, as well does the lazily soaring turkey 

 buzzard, the strange barn-owl, the casual opossum, the groves of sweet-gum 

 trees, and other no less characteristic features. To be sure these sometimes are 

 seen beyond the fall-hne, but never so abundantly as on the Coastal Plain to the 

 south. 



IV 



The existing forests of eastern North America probably date back to the 

 Miocene period. At that time a mild cHmate, most probably a warm temperate 

 cHmate, enveloped the circumpolar area, and a luxuriant vegetation flourished 

 to within at least twelve degrees of the north pole. Professor Heer and other 

 students of paleobotany have found in the Tertiary deposits of Greenland and 

 Spitzbergen a large number of fossil remains of plants which are closely allied 

 to forms now living in eastern Asia and eastern North America. Among these 

 are a number of forest trees, identical in some instances with existing species, 

 as the hquidambar, the tulip tree (Liriodendron) , the sassafras and magnoHa. 



