A REVOLUTION IN EGG PRODUCTION 71 



Flocks may be found which are excellent layers, and 

 other flocks which are very poor layers, in cases where both 

 kinds of flocks are produced from eggs obtained from the 

 same source, and under identical conditions. 



Nothing in the world but the effect of environment can 

 account for such cases. It all depends on "the man behind 

 the gun." One man hits the bull's eye — the other shoots wide 

 of the mark, in providing environment. 



In other words, we must supply such environments as 

 will enable the stock to back up their reputation, and prove 

 out on their heredity. 



This little book, up to this point, has been dealing mostly 

 with this second factor, of environment. The book, however, 

 would never have been attempted, except as a result of a 

 study of the third factor mentioned in the preface, which is 

 "the length of the hen's business day." 



The author had noticed for several years that, irrespec- 

 tive of extreme temperatures, the egg yield fell off in late 

 fall and winter as the days got shorter, and that this falling 

 off occurred even faster during cloudy and dark seasons, 

 which were comparatively mild, than during bright sunshiny 

 seasons of colder temperatures. 



This condition was so obvious that the author decided 

 that he would, at some time, experiment with an artificial day. 



A Hen's Business Day 



On June 21st, in the latitude of Chicago and Boston, the 

 sun rises at about four twenty-three a. m. and sets at about 

 seven forty p. m., making a day of fifteen hours and seventeen 

 minutes; and in the same latitude, on December 21st, the sun 

 rises about seven twenty-six a. m. and sets about four thirty- 

 one p. m., making a day of nine hours and five minutes. This 

 is a difference in the length of a hen's business day of six 

 hours and twelve minutes. 



This variation in the length of a hen's business day only 

 tells a part of the story. The days in summer are nearly 

 always light enough for the hens to transact business for their 

 whole length ; but many of the short days of winter will be 

 so dark and dreary as to restrict the hens to a business day 

 of seven hours or less. 



