No. 596] EGG PRODUCTION AND SELECTION 481 



bird that begins to lay in November and lays 2 eggs that 

 month, 10 in December, in January and 8 in February, 

 although she lays the same number of eggs as the individ- 

 ual that began February 1. The former is clearly a 

 mediocre producer, the latter a high producer of late 

 maturity. 



The flock averages for the past winter, arranged ac- 

 cording to the month in which the birds were hatched, are 

 instructive on this point. The mean egg production for 

 the (140) March-hatched birds was 39.8 eggs, for the 

 (172) April-hatched 29.81, and for the (158) May-hatched 

 18.1 eggs. If the pullets be grouped according to Pearl's 

 classification of zero, 1 to 30 (mediocre), and over 30 

 (high), there were among March-hatched pullets 6.4 per 

 cent, zeros, 30.0 per cent, mediocre, and 63.6 per cent, 

 high; among the April pullets 11.6 zeros, 37.3 per cent, 

 mediocre and 51.1 per cent, high ; while among the May- 

 hatched pullets there were 19.9 per cent, zeros, 58.8 per 

 cent, mediocre and only 21.3 per cent. high. The average 

 winter production for the mediocre and high producers 

 respectively, is for March-hatched birds 17.2 and 54.6 ; for 

 April 16.6 and 46.2; for May 16.1 and 40.7. In this con- 

 nection it should be recalled that there is a tendency for 

 the abstract numbers involved to yield similar averages, 

 which are an indication to some extent at least of two 

 genotypes rather than one. Clearly, the time of year dur- 

 ing which a Ehode Island Red pullet is hatched plays an 

 important part in determining the class in which a given 

 individual falls. 



In general the use of a hen's record expressed in num- 

 ber of eggs per unit of time as the sole criterion of her 

 capacity for egg production seems to us to be essentially 

 wrong. Attention should also be directed to the elements 

 that enter into the make-up of the record. The factor of 

 maturity is not wholly a fecundity factor, though it is 

 closely bound up with egg production and may modify a 

 pullet's fecundity record very considerably. Broodiness 

 is another factor that, although closely associated with 



