INHERITANCE OF FECUNDITY 217 



B. With 5 9 9 indicated to be of class 4 = fLih . FLih. 



9 Progeny 



Winter* Production: Over 30 Under 30 Zero 



Observed 6 6 



Expected 6 6 



Mean winter productions of all 



9 9 in indicated class 69.00 eggs 15.83 eggs 



All 9 Progeny 



Winter Prodnctio?i: Under 30 Over 30 Zero 



Observed 8§ 15^ 5 



Expected 10. S5 14.5 4.25 



Mean winter production 00.50 eggs 12.26 eggs eggs 



One of the five females ( 9 397) of class 4 actually laid 31 eggs 

 in her winter period and hence was hterally an 'Over 30' bird. 

 There can be no doubt, however, that this record is merely a 

 fluctuation, and that 9 397 is really a class 4 bird of the constitu- 

 tion indicated. This is shown by her progeny. 



Matings of a Barred Plymouth Rock male of class 1 . Males of 

 class 1 are extremely interesting both from the theoretical and 

 the practical standpoint, since they are homozygous with respect 

 to the presence of both fecundity factors. In consequence, all 

 the daughters of any male of this class, regardless of the females 

 with which he is mated, should be high producers. In the course 

 of the experiments here under discussion only one male of this 

 type has been used in the breeding pens, and owing to an unfor- 

 unate accident he was available for breeding only during a single 

 season. This & no. 550 was a remarkably fine and vigorous bird. 

 He was easily the best bird, in respect to all fancy and utility 

 points, out of the hundreds of cockerels raised the same year. He 

 produced by the mating of a class 3 d' (o" 68, p. 000, supra) and a 

 class 1 9 . That is, 



(cf 68) /L1L2 . fhU X /L1L2 . FUh ( 9 C161) 



i 



0^550 



/L1L2 . JLiU 



THE JOURNAL OF EXPERIMENTAL ZOOLOGY, VOL. 13, NO. 2 



