EGG PRODUCTION. 83 



«heep. He says (p. 12) : "Mr. H. C. Stephens of Chalderton, 

 Salisbury, by breeding from twin-bred rams and ewes for some 

 years past, has noticeably increased the fertility of his flock of 

 Hampshire Down sheep." Further details regarding this 

 experiment are given in the original. In general there can be 

 no doubt that there is need for much more extensive and exact 

 experimental and quantitative evidence than we now have 

 before it will be possible to reach any positive conclusion as to 

 the extent and degree of inheritance of fertility among mammals. 



SUMMARY. 



This bulletin describes the results of an experiment in which 

 "registered" pullets (daughters of "200-egg" hens) are com- 

 pared (a) with their mothers, and (b) with "unregistered" pul- 

 lets (not daughters of "200-egg' hens, but otherwise of the same 

 breeding) in respect to egg production, when given the same 

 treatment as to housing, feed and the like. These results may 

 be summarized as follows : — 



1. The daughters of "200-egg" hens were in this experiment 

 very much inferior to their mothers in average egg production. 

 This is particularly true of winter egg production. 



2. This experiment gives no evidence that there is a sensible 

 ■correlation between mother and daughter in respect to egg pro- 

 duction, or that egg producing ability is sensibly inherited. A 

 relatively high producing mother was as likely as not to have 

 relatively poor producing daughters in this experiment. 



3. In this experiment the daughters of "200 egg" hens were 

 not such high egg producers as pullets whose mothers' egg 

 records fell in the 150-200 egg class. The daughters of "20a- 

 egg" hens were most inferior (proportionately) to the "unreg- 

 istered" pullets in respect to winter egg production. 



4. The daughters of "200-egg" hens were in this experiment 

 somewhat more variable (that is, conformed less closely to 

 type) in respect to egg production than were the "unregistered" 

 pullets. No special stress is to be laid on this greater variability. 

 The significant thing is that the "registered" pullets were not 

 less variable than the "unregistered." 



It must be remembered in considering these results respecting 

 the inheritance of egg producing ability that they are not to be 



