POULTRY NOTES — 1909. 93 



From these tables the following points are to be noted : — 



1. The fertility of the eggs during the hatching season in 

 which these hybrids were raised was relatively very high for the 

 pure bred birds, both Barred Plymouth Rocks and Cornish 

 Indian Games. The average percentage of eggs infertile from 

 all the Barred Plymouth Rock pullets used as breeders during 

 that breeding season was 13.65 ± 1.38.* The average percent- 

 age of eggs infertile for the pure Cornish Indian Game matings 

 shown in Table 6 above is only 10. In both cases (Barred 

 Rocks and Cornish) the figures given include all the eggs 

 set throughout the whole of the hatching season from early 

 in March until the middle of May. No data were omitted in 

 making up these general averages. . It is evident from these 

 average figures of 13 percent and 10 percent of infertile eggs 

 that (a) the environmental conditions were favorable for secur- 

 ing high fertility of eggs during the hatching season of 1909 

 and (b) that the breeding stock of both pure breeds was vigor- 

 ous and in good condition. It is doubtful whether fertility 

 records sensibly lower than 10 percent of infertile eggs for the 

 whole hatching season can be expected with large flocks of 

 birds. 



2. It will be noted from Tables 4 and 5 that the per- 

 centage of eggs infertile in the hybrids was quite different 

 according to the direction in which the cross was made. In 

 the case of the cross considered in Table 5 (Barred Rock J* 

 X Cornish 5) the percentage of eggs infertile is very low, 

 amounting to only 4 percent for the whole season. This, 

 it will be noted, is a better average result than was obtained 

 with either the Barred Rocks or Cornish Indian Games when 

 pure bred during the same season, and kept under the same 

 environmental conditions throughout. On the other hand, the 

 fertility of the eggs in the reciprocal mating (Cornish Indian J* 

 X Barred Rock $) was very much reduced, as is shown in 

 Table 4. Taking the whole season through and averaging 

 the results obtained from two different male birds used in this 

 cross the percentage of eggs infertile is 24. This is six times 

 as great a percentage of infertility as was obtained in the other 

 cross, and is practically twice as great as the highest percentage 



^Cf. Me. Agric. Exp. Station Bulletin 168, Table VI, p. 119. 



