DWARF EGGS OF DOMESTIC FOWL. 303 



birds, or, 4.67 per cent, laid one or more dwarf eggs. The 

 close agreement of the two approximations indicates that about 

 5 per cent, of the birds in an average flock will produce at 

 least one dwarf egg. 



VI. The Seasonal Frequency of Dwarf Eggs Compared 

 to Normal Eggs. 



Dwarf eggs are frequently found by poultrymen during the 

 spring and early summer and somewhat less frequently at 

 other seasons. During the eight years that these eggs have 

 been collected at the Maine Station plant they have occurred 

 during every one of the twelve months. However, 70.8 per 

 cent, of them were laid during the five months from March t 

 to July 31. During some years more than 80 per cent, were 

 produced during these months. Table 5 gives the number of 

 dwarf eggs produced each month for each of the eight years 

 (1908-16). It also gives the percentage of all of the dwarf 

 eggs (1908-16) and the percentage of the total annual yield of 

 normal eggs (1899-1907) 11 produced during each calendar 

 month. 



This table shows that both dwarf and normal egg produc- 

 tion is higher during the spring and summer than during the 

 fall and winter. A comparison of the percentages at the foot 

 of the table, however, shows that for May, June and July the 

 percentage of the annual dwarf eggs is greater than the per- 

 centage of normal eggs. The monthly percentages of both 

 normal and dwarf eggs are shown graphically in Fig. 52. It 

 will be noted that the two polygons do not begin or end with 

 the same month. The reason for this is that the data for the 

 total egg production was collected for the September and Octo- 

 ber after the birds were one year old, while for the period 

 during which dwarf egg production was studied, the data from 

 September 1 to August 31, more nearly represents the data 

 from a single group of birds. 



"These percentages were determined by Pearl, R. and Surface, F. M. 

 191 1. A Biometrical Study of Egg Production in the Domestic Fowl. 

 II. Seasonal Distribution of Egg Production. U. S. Dept. of Agr., 

 Bur. of Anim. Indus. Bui. no, Pt. II, pp. 81-170. 



