Vol. XVII 
1900 
PALMER, The Maryland Vellow-throat. 235 
from the southwestward and traveled a much greater distance 
in going to and from their winter habitat in Mexico and Central 
America. Thus birds of the same subspecies occurring in the 
same latitude at the same or a different elevation and in adjoin- 
ing counties, are divisible into two groups according to size, the 
difference being due to the contrast in the length and direction 
of their migrations. This result is peculiar and interesting, and 
in line with the already known fact that many eastern Mississippi 
Valley migrants reach New York State, and pass even further 
east. 
The eastern trend of the Atlantic coast line is an important 
factor in the migration of brachidactyla. ‘Twenty-six spring spec- 
imens collected in the Bahamas by the naturalists of the U.S. 
Fish Commission Steamer ‘ Albatross’ are true dbrachidactyla, 
though somewhat darkened and weathered. They undoubtedly 
were on their way to northern New England, Nova Scotia, or 
Newfoundland. 
While on Smith’s Island, Virginia, in May, 1898, L saw some 
three dozen Yellow-throats which, with other birds, had struck 
the lighthouse ten days previously. They all were drachidactyla 
and mostly males. Several struck the lighthouse on the evening 
of May 21, and I secured three females; they were the same 
form. The resident birds on the island, which are abundant 
and slightly larger than typical ¢vzchas, were all paired and breed- 
ing at the time. 
Maryland Yellow-throats are frequently mentioned by writers 
as being abundant during migrations at lighthouses along the 
coast; they of course are drachidactyla. ‘This and the occurrence 
of the form in abundance during migrations in the Bahamas 
readily suggests the idea that the migration course is almost if 
not entirely southward in the autumn; that birds bred in New 
England and eastward migrate toward the coast and thence over 
the sea through the Bahamas to the West Indies. 
This suggests the probability of a former narrower separation 
of the islands from the continent. 
The birds of the Mississippi drainage area are larger as we go 
northward but do not attain the pointed wing and long outer 
primary characteristic of typical drachidactyla. The western bird, 
