Nos. 618-619] EGG PRODUCTION 



305 



TABLE VIII 



gg Production of Pullets Hatched in April, May and June, 1915; 



Note.— The data above the double bar is for birds that completed the 

 year. A part of the data below the double bar was compiled at the end of 

 the winter and thus includes some birds that died during the summer. 



birds is 40.5. The means of the under-thirty class are 

 18.8 for February and for the other three months ap- 

 proximately 16 eggs. Now, the mean for the abstract 

 numbers 1 to 30 is 15.5, a value which is not far from 

 the observed mean, since the value of 18.8 eggs obtained 

 for the February birds is probably due to the small num- 

 ber of individuals involved. As the value of the mean 

 for the under-thirty birds is practically alike in all cases, 

 and as the value of the means for the over-thirty class 

 for the various months decreases with decreasing age, 

 it is evident that the value, 16.1, comes mainly from the 

 relation of the abstract numbers and has little or no sig- 

 nificance in itself. This point will be returned to shortly. 



It will be noted in Table VI that the percentage of over- 

 thirty pullets dropped very suddenly in passing from 

 April to May. It means, I take it, that many of the May 

 hatched birds did not reach a winter egg production of 30 

 eggs or over because of the time they were hatched. In- 

 deed, something of this sort is to be expected when a 

 definite number of eggs is taken for a dividing line at a 

 particular point on the calendar. If the production curve 



