l66 MAINE AGRICULTURAL EXPERIMENT STATION. I9II. 



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 em- 

 phasized by Nilsson-Ehle,* that phenomena of mutation are, in 

 many cases at least, merely cases of Mendelian segregation has 

 much evidence in its favor. 



The pedigrees which have been given are merely illustrations. 

 Many other similar ones might be cited from the records in hand 

 did space permit. In the experiments dur ng 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. Simi- 

 larly, 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 laying 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 Novem- 

 ber 10 and March i 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. E 356 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 breeding season only one pullet worth 

 putting into the laying house. This pullet (F163) made a win- 

 ter record of but 11 eggs. F163 was bred in 1910, but produced 

 only one daughter worth saving. This daughter, G429, has 

 made a winter record of 18 eggs. It would be hard to get 

 clearer evidence than that afforded by this breeding history that 



* Nilsson-Ehle, H., "Kreuzungsuntersuchungen an Hafer und Weizen," 

 Lunds Univ. Arsskr., N. F., Afd. 2, Bd. 5, Nr. 2, 1909, pp. 1-122. 



