346 MAINE AGRTCUI,TURAI, EXPERIMENT STATION. I912. 



B. With 42 2 ? indicated to be of classes 3, 4, or 6 — fL^h. Phh or 

 fLJ,. FLJ, or fkL,. FIJ,. 



All 2 Progeny 



Winter Production: Over ^o Under _^o Zero 



Observed i6i i i 



Expected 18 



Mean winter production of all 

 5 ? in indicated class 51 -25 eggs i o eggs 



^See p. 312 for explanation of the convention of dividing the birds 

 Virhich lay exactly 30 eggs in the vi?inter period. 



The one daughter f F379) with the zero record was evidently 

 abnormal in respect to her reproductive organs. During the 

 last days of September and early October she began and kept 

 up for a period of over a week daily visits to the nest (cf. 

 section on "Matings of Barred Plymouth Rock males with 

 Barred Fi females") This is normally a .ywr^ indication of ap- 

 proaching laying. Further, birds which begin in this way not 

 only are precocious in laying but make high winter records. 

 This bird, however, stopped at once, and neither visited a nest,, 

 nor laid until late the next spring and then laid only a few 

 eggs. There is little doubt that in this case the hereditary basis 

 for high production was present ( LiL-.) but failed of expression 

 for purely physiological reasons. Unfortunately no post-mortem 

 examination of this bird was made, the fact of her abnormality 

 not having been recognized until too late to make such an exam- 

 ination possible. 



It was unfortunate that $ 550 could not have been used dur- 

 ing several breeding seasons. Even with the limited progeny 

 actually available, however, the contrast between this bird and 

 the others which have been discussed above is sufficiently strik- 

 ing. 



Dotibtful cases. In 1908 a Barred Plymouth Rock $ no. 61 

 was successfully mated with 399. The winter production 

 records were as follows ; 



Mothers' ■winter production Daughters' zvinter production 



2 D157 Under 30 i over 30 o tinder 30 zero 



* 2 D168 Over 30 2 over 30 10 under 30 i zero 



2 D90 Under 30 2 over 30 5 under 30 o zero 



