12 THE OSPREY. 



possibility of their descent below and through the cloud surface, for the 

 clean mountain raasses offered a very inviting field for their early morning 

 sear ah for food. 



I was able to devote but little time to discover the presence of the same 

 species in the low grounds, as about Luray, but on my return through Luray, 

 and after spending a night there I did not see a single species that I had 

 noted on the mountain. Kingbirds, Sparrow Hawks, Blackbirds and Meadow - 

 larks were abundant in the valley. During the night in Luray and early in 

 the morning mist hung suspended over the valley at a considerable height, 

 the same mist of which I had frequently seen thei compact surface from the 

 mountain and which is a never failing source of interest to the campers of 

 Stony Man, many of whom often watch its changing surface from Sunset 

 Rock as the morning sun and rising breeze compel it to reveal the beautiful 

 landscape almost 3,000 feet below. 



Tho' undoubtedly the migrating swarms sighted the cloudless mountain 

 tops as soon as the light was sufficient, I do not believe that the mountain chain 

 was a factor in determining the direction of their flight. 



About Washington, some sixty miles eastward, and where there are no 

 mountains, I have often seen during the same period all the species seen on 

 Stony Man. Besides, the trend of the Blue Mountains is to the southwestward. 

 It seems an evident truth, therefore, that the presence of these birds in such 

 large numbers at this elevation in the early morning was due to the fog condi- 

 tions of the low lands; that probably the same species were not present beneath 

 the fog on the same morning, and that the mountain chain is not a f;ictor in 

 determining the direction of the migration. In all my experience with the 

 birds of northern Virginia, I have discovered but vei'y little evidence that the 

 configuration of the surface is a factor in determining the direction of the 

 flight of migrants in either direction of the land birds. The general move- 

 ment is southward, or east of south, so that the tendency is to reach the coast, 

 where they often occur in immense numbers. 



The Potomac River, however, is a great highway for many species of 

 water birds, and many accounts of the unusual species along this ancient water- 

 way are bat a few of the steps of a migration which is regular, common to 

 many species, and which began long before the present configuration of the 

 region became fixed. 



