66o Selection of Fowls for Egg Production, [nov., 



November ist of the year in which the bird is hatched to 

 November Est of the following- year. In the absence* of 

 records of egg production during the entire lifetime of a hen, 

 and of extensive data of any longer time unit, this "first 

 year's egg production" has been taken as a measure of the 

 total ability of a bird to produce egg's. Although not a precise 

 measure of such ability, the first year's production is believed 

 to have a high value for the purposes of inquiry, in that the 

 egg production in this first year is the greatest in the life- 

 time of the hen and decreases each subsequent year, so that 

 the first year's production, on an average, constitutes a con- 

 siderablv larger part of the unknown total production than 

 docs that of any other equal period of time. Again, the period 

 is a sufficiently large unit to include the influence of season, 

 as well as other influences such as, for example, the original 

 mating season, time of moulting, and the like. 



Records are available of the first year production of eggs 

 in iSoo-iooo of 70 Barred Plymouth Rocks and 70 White 

 Wvandottes; in 1900-1901 of 85 Barred Plymouth Rocks and 

 72 White Wvandottes; in 1901-2 of 4S Barred Plymouth 

 Rocks and 33 White Wvandottes. After this year Barred 

 Plymouth Rocks only were used. In 1902-3 records are 

 available for 147 birds, in 1903-4 for 254, in 1004-5 for 283, 

 in 1005-6 for 178, and in 100O-7 for 1S7 birds. The years 

 1902-3, 1003-4, 1005-6, and 1006-7 were, however, abnormal 

 years, the records for 1003-4 and 1006-7 relating to eleven 

 months only, and those for all four years being affected b\ 

 mishaps. Owing to these defects in the statistics, the data for 

 one vear are probably not strictlv comparable with those for 

 anv other vear. The statistics for each year have to be 

 treated separately, and whenever comparisons between years 

 are made, great caution has to be exercised in drawing 

 conclusions. 



Variation in Annual Egg Production . — The statistics are 

 examined by the methods of biometrical analysis. Omitting 

 the mathematical conclusions reached, it may be said that 

 there was no marked change in the average annual egg pro- 

 duction. The following table shows the changes in average 

 annual production between 1S99 and 1007 in the case ot 

 Barred Plymouth Rocks, corrections being applied to the 



