456 THE POPULAR SCIENCE MONTHLY. 



a milch larger scale and much more pronounced in character, as 

 are present in the settled Eastern portion, namely, an open grass- 

 covered region bordered by a vast forest. The same conditions 

 hold good as in the case of the smaller areas of field and wood- 

 land, and we are not surprised to find differences in life of a cor- 

 responding nature. A fauna and flora distinct and characteristic 

 of the prairie region on the one hand are in contrast with a more 

 or less distinct forest life. 



America at the time of its discovery presented a vast and un- 

 broken expanse of forest embracing all the now cleared and 

 thickly settled portions of the Eastern wooded region. Early ex- 

 plorers, as their records clearly show, were forcibly impressed 

 wrth this endless reach of forest. The past two centuries have 

 witnessed the steady downfall of the woods and their conversion 

 over a wide territory into fields of grain and grass. Conditions 

 of a prairie nature have, in other words, been introduced into the 

 forest region, and we are naturally led to reflect upon the effect 

 that this has had upon the life. When the region was one un- 

 broken forest, where were the birds that to-day are found only in 

 our fields ? 



Two solutions of this problem offer themselves to the mind. 

 There has either been a radical change of habit among certain 

 species in the past two hundred years, or an emigration and occu- 

 pancy of the new lands have taken place from the prairie regions 



on the "Western border. This 

 latter view is, I think, the more 

 probable from the fact that all 

 the above-mentioned field birds 

 are found on the plains or are 

 represented there by varieties 

 which differ only in slight 

 shades of color. 



The range of the vesper spar- 

 row covers the entire United 

 States from the Atlantic to the 

 Pacific and north to the plains 

 of the Saskatchewan, so that it 



Fig. 4.— Black-throated Bunting. appears to be equally at home 



in the Eastern fields and on the 

 Western praries. A paler variety occurs in the middle province, 

 undoubtedly the result of the arid conditions of the region. Equal- 

 ly as extensive is the range of the savanna sparrow, though in 

 the choice of localities it is not so entirely an upland bird as the 

 vesper sparrow, haunting marshes along the coasts and river val- 

 leys as well as the higher open country. Several geographical 

 races occur in the West and North. The little grasshopper spar- 



