INTRODUCTION. 19 



bird-life, and therefore afford the richest field for the ornithologist. 

 The willows are the chosen home of the Prothonotary Warbler 

 {Protonotaria citrea); the undergrowth, of the Hooded and Blue- 

 winged Yellow Warblers {Sylvania jnitrata and Helminthophila pinus); 

 ducks and other aquatic species have a secure home in the shelter 

 of the water-lilies ; herons build their nests in the lofty tops, and 

 turkey buzzards hide their young in the hollow bases, of the gigantic 

 sycamores. Thirty years or more ago. Parakeets {Conurus caroUii- 

 ensis) disturbed the solitude or drowned the voices of the songsters 

 by their piercingly shrill screeching notes, but they have long 

 since vanished, never to return. The turkey still lingers, how- 

 ever, but must surely disappear when its shelter shall have passed 

 away. 



Climate. The climatic conditions of Eastern North America 

 are remarkably uniform, as might be expected from the exceeding 

 simplicity of its topographical features. The Alleghany mountains, 

 although sufficiently elevated to carry on their summits many 

 Canadian types, both of plants and animals, quite to the southern 

 limits of the range, in northern Georgia and Alabama, yet form 

 so slight a barrier that a very large majority of the species in both 

 the animal and vegetable kingdoms are common to the Atlantic 

 seaboard and the Mississippi Valley. In fact, diversity of flora in 

 the two regions is usually due chiefly to local causes — character of 

 soil and geological formation — it being a common circumstance to 

 find localities along the Atlantic coast and in the interior which 

 more resemble one another in their vegetation than do contiguous 

 localities in either district. 



It is a well known fact, however, that in the interior of large 

 continents the climate reaches greater extremes of temperature than 

 in the same latitudes along the seacoast; and this principle applies 

 to the districts here under consideration, though to a very slight 

 extent. From the meteorological records of the United States Signal 

 Office, we are able to deduce the information that, as a rule, in 

 cases where the mean annual temperature is essentially the same 

 at places of corresponding latitude on the Atlantic coast and in the 

 Mississippi Valley, the annual range is greater in the latter; that 

 is, the maximum heat of summer and minimum cold of winter excel 

 those of the former. The rainfall also, as a rule, is somewhat 

 heavier along the coast. There are many exceptions, however, to 

 these rules, and instances can be found where, according to the 

 records, they are reversed. 



