285 
Since 1952 is the first year a brood survey was made from the air, no data 
from previous years are available for comparative purposes. The information 
obtained will provide a basis for work in future years. Many areas can be 
eliminated from consideration, while other areas may receive more intensive 
sampling. It is to be expected that a sampling procedure will evolve to provide 
the most complete and accurate coverage with the minimum of time and expense. 
