UNITED STATES DEPARTMENT OF AGRICULTURE 
BUREAU OF BIOLOGICAL SURVEY 
WASHINGTON, D. C. 
February 3, 1910. 
Mr. William Brewster, 
145 Brattle Street, 
Cambridge, Mass. 
Dear Brewster: 
Replying to your letter of January 30 I regret to say that I 
do not know of any way by which the age of a duck killed in winter 
may be positively determined. By cleaning the skeleton it would 
probably be possible to distinguish a bird of the year from an 
adult, but without going to this trouble I do not know how the 
thing coula be done. 
I have consulted several persons who are in the habit of 
purchasing poultry for the table and am informed that they know of 
no means by which young of the preceding spring can be told with 
certainty from the adults. 
Very truly ymirn. 
T 
