50 Maine: agricultural lxperimlnt station. 1903. 



other lot, and the conclusion drawn that one lot had right and 

 the other lot wrong conditions. Or, if differently divided, the 

 results might not have been so pronounced, but equally unreli- 

 able. 



The incubation tests made in 1902 were undertaken in the 

 belief that the knowledge of the source and history of every tgg 

 would enable us to avoid disturbing causes and leave onlv the 

 leading questions for consideration. Had the investigations 

 been made with eggs taken from the flock or pens of hens, as 

 laid, without reference to the individual sources from which they 

 came, and divided into lots, and subjected to the conditions of 

 the test, results could have been secured that, unquestioned, 

 might have seemed to give positive evidence, pro or con, and 

 which might have been published without any suspicion that the 

 results were untrustworthy. 



In the twelve incubation tests which we have made this year, 

 but not reported, the eggs from each hen were divided, in the 

 order in which they were laid, by alternation, into two lots in 

 each test. The result of such division, if applied to hen No. 

 511 would have given one chick hatched from lot i and two 

 chicks hatched from lot 2, and yet the results would not have 

 been produced by incubation conditions, but rather by some 

 previous conditions for which we could not account. No. 511 is 

 discussed because she is first on the list ; what is true of her holds 

 good in a greater or less degree with many others. 



Could eggs of known fertility be secured, incubation tests 

 could be made that would be simple and reliable. In the light of 

 the data given in the table and that obtained in the twelve incuba- 

 tion tests there appears to be no means of securing positive 

 information regarding this point. In the absence of positive 

 information probably the best plan to pursue is to secure birds by 

 test that yield eggs of uniformly high fertility and rely upon the 

 averaging of the results of many incubation tests. In this test 

 the birds were by no means fresh, but had been working several 

 months. 



It does not appear that heavy yielding is a hindrance to fertility 

 if the birds have had a period of rest following it, and resumed 

 heavy work. 



One of the first birds found to yield over 200 eggs per year in 

 1899 was No. 4. During the first year she laid 201 eggs ; 140 

 the second, 130 the third, 119 the fourth, and she is now doing 



