DELAWARE VALLEY ORNITHOLOGICAL CLUB. 15 



character of this flat lowland, broadening toward the south and 

 extending around the foot of the southern Appalachian Plateau 

 into the bottom lands of the Mississippi and Ohio drainage, in- 

 duced the spread of a more or less similar type of vegetation 

 throughout its whole extent. In the narrow northern Atlantic 

 portion of this coastal-plain lowland the tree-growth is strikingly 

 like that which prevails farther to the south and in the interior. 

 It is predominantly a hardwood growth of broad-leaved decidu- 

 ous forms of great variety. This forest, which finds its best 

 expression in the interior lowlands, is intimately related to 

 humid conditions and to soils of alluvial character. Such species 

 as the Sweet Gum (Liguidambar), the Swamp Bay (Magnolia 

 virginiana), the Pepperbush (Clethra), and certain oaks, besides 

 several other forms, are highly characteristic. These broad- 

 leaved trees find the conditions of their growth in meadow soils 

 of a deep loamy character, while in the extensive sandy tracts 

 throughout the coastal-plain area pines are the prevailing wood- 

 land, forming the familiar "pine barrens." 



Faunal distribution is very closely associated with the spread 

 of certain types of vegetation, and it seems highly probable that 

 the presence of the Carolinian fauna in the lower Delaware 

 Valley is thus an integral part of the coastal-plain forest. As 

 this forest, finding suitable soil conditions, gradually came to 

 occupy the slowly uplifting margin of the continental shelf, its 

 animal life likewise spread with it. 



Birds, from their comparatively high organization and their 

 great freedom of movement, are exceptionally sensitive elements 

 in any faunal group and are thus an indication of changes 

 within a given region. Certain species are clearly related to 

 certain habitats and a particular habitat is fundamentally de- 

 pendent on vegetation which in turn is conditioned by the char- 

 acter of the soil, climate, of course, determining the broader 

 phases of range. It is a well-known fact, as Mr, M^itmer Stone 

 observes in a recent letter to the writer, that "certain birds like 

 the Prairie Warbler seem to be typical of the sandy coastal 

 plain and occur only in it, just as with most of the coastal plain 

 plants. The Gnatcatcher and Mockingbird are perhaps other 

 species of similar distribution. Other Carolinian species like 



