No. 534] FECUNDITY IN THE DOMESTIC FOWL 337 



The subsequent breeding history of E248 indicates 

 that it was probably a DD bird, though the reasons for 

 this opinion can not be fully gone into here. The general 

 view, recently emphasized by Xilsson-Ehle, 13 that phe- 

 nomena of mutation are, in many eases at least, merely 

 cases of Mondolian segregation lias much evidence in its 

 favor. 



The pedigrees which have been given are merely illus- 

 trations. Many other similar ones might be cited from 

 the records in hand did space permit. In the experi- 

 ments during the past three years the attempt has been 

 made to propagate separately lines of high, medium and 

 low fecundity. In the course of this work it has been 

 found that lines of high fecundity were nearly if not 

 quite as likely to have originated with individuals of a 

 low record of production as with those of a high record. 

 Similarly, many low fecundity lines have originated with 

 individuals which were themselves exceedingly high 

 layers. Indeed one of the highest winter layers which 

 have ever appeared in the stock evidently belonged to a 

 genotype of very low fecundity, since it has never been 

 able to produce progeny of anything but the poorest lay- 

 ing capacity. The breeding history of this bird (D352) 

 is indeed so interesting that it may be briefly discussed 

 here. This bird in her pullet year laid 98 eggs between 

 November 10 and March 1 and made a record for the 

 year of over 200 eggs. She was mated and produced 

 plenty of eggs during the hatching season, but they 

 hatched very badly. Only one female worth putting in 

 the house was obtained. This pullet (E356) made a 

 winter record of only 39 eggs, just about the general 

 flock average. E356 was not mated. Her mother (D352) 

 was kept over and bred to another male the next year, in 

 the hope that as a fowl she might produce more and 

 better chickens than she had as a pullet. As a matter of 

 fact she was again able to produce during the whole 



Lund.s Univ. Arsskr., X. p., Afd. 2, Bd. 5, Xr.2, 1909, pp. 1-122. 



