138 Farm Poultry 



intermediate grades, it is impossible to draw a 

 definite line of separation which shall divide the 

 fertile from the infertile ones. 



Fresh eggs are to be preferred for hatching, 

 although good hatches from eggs that were kept 

 several weeks are reported. Eggs are sometimes 

 sent long distances and still retain their vitality 

 sufficiently to produce a good number of strong 

 chicks. The following is quoted from an experi- 

 ment station publication : * " Where the incubator 

 is placed in a room whose temperature is reason- 

 ably even and is properly managed, a high per- 

 centage of hatch may be expected only (a) when 

 the hens have plenty of exercise, (6) when the 

 eggs are freshly laid." 



After the male is removed, the eggs are 

 thought to be fertile for a few days, "from four 

 to fourteen days" is given by some authors. The 

 following gives the results of definite observa- 

 tions :f "On the farm of the Ohio State Univer- 

 sity 40 Leghorn hens which had previously been 

 kept without males were placed in pens with the 

 male birds February 18, and the percentage of 

 fertile eggs observed for nine days after mating. 

 This increased regularly from 0, on the day of 

 mating, to 95 per cent on the eighth day after 

 mating. July 1 the males were removed from the 



* Bulletin No. 158, Michigan Agricultural Experiment Station, 

 t Agricultural Student I (1894), in Experiment Station Record. 



