258 



Eael W. Benjamin 



began laying in December and continued laying for about the same period 

 as the others (until August). No material difference can be observed 

 between the types of curves shown in figure 31, and those shown in 

 figures 28, 29, and 30. There seems, then, to be no marked error due 

 to the possible- selection of birds in the study of the random flocks, and 

 it "is probable that the curves for heavy producers are not materiUly 

 different from those for lower producers. 



. ^ J -' ) ' 



Grams 

 65 



63 



61 



59 



57- 



Deo. 



Jan. 



Feb. 



March 



April 



May June July Aug. - 



Fig. 31. mean monthly size records for five normal individuals for a period 



OF FIVE years 



After the great increase in the size of the eggs from the first to the second 

 year, there seems to be a gradual decrease in the size of the eggs produced 

 during successive years. This last statement does not agree with the 

 results of Curtis (1914 a). 



. No decreased size of the eggs produced at the beginning aod at the end 

 of the fitter is observed, as claimed by F6r6 (1898 b) and Curtis (1914 a), 

 and there is no appreciable difference in the variations for the birds laying 

 large, medium, and small eggs (fig. 30). 



