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THE AMERICAN NATURALIST [Vol. XLIX 



genetically mediocre winter producers which was used in 

 the Mendelian analysis. In the year 1905-06 the mean 

 winter production was 41.95 eggs. In 1913-14 the pro- 



duction in the corresponding months was 51.20 eggs 

 per bird. 



3. It was shown by Pearl and Surface that, on the 

 average, a flock of hens produces 81.73 per cent, of their 

 total annual yield between November 1 and August 1. 

 Applying this figure to the 1913-14 nine-month total of 

 135.82 eggs, we get for the probable production of this 



9 "Biomedical Study of Egg Production in the Domestic Fowl. IT. Sea- 

 sonal Distribution of Egg Production," U. S. Dept. of Agr., B. A. I. Bull. 

 110, Pt. II, p. 89, 1911. 



