104 MASS. EXPERIMENT STATION BULLETIN 211. 



laying flock of 1917-18, partly through a fortunate nick between a single 

 pair. 



Meanwhile, the intensive work on broodiness had given a flock com- 

 paratively free from broodiness, so that it was known that broodiness 

 could be very much reduced even if not eliminated. The next step was 

 an attempt to fuse the low-broody strain, which were poor producers, 

 with the early maturing line, which were good laj^ers, by choosing non- 

 broodies from the latter and good layers from the former. Of course, it 

 was expected that the fusion would result in a temporary setback. The 

 first year after the fusion, 1919-20, fewer eggs were laid and more broody 

 birds occurred in the combined flocks than in the respective contributing 

 strains, but this difficulty has been overcome. On reviewing the situa- 

 tion, it is clear that the desired objective would have been reached had 

 the non-broody members of the high line alone been used, for these birds 

 are the ones that constitute the major portion of the ancestry of to-day's 

 flock. 



While concentrating on maturity and broodiness, some progress has 

 been made in eliminating the winter pause, and in securing larger numbers 

 of birds that lay at a high rate. Data covering these statements are given 

 in later sections of the paper. The proportion of birds in the flock that 

 approach the desired type is much greater. With the increase in the 

 number of birds approaching the desired type, birds with records that 

 would have qualified them for breeders in the early stages of the work 

 are now rejected. The basis of selection has been progressively altered 

 and selection made progressively more stringent, as shown in Fig. 3 and 

 Table I. 



In each case those mothers only are included having daughters with a corresponding record. 

 Because of the clean-up in June, 1920, an exception is made so that the annual production for 

 1919 is for birds having daughters that laid up to June 1. For the first four years birds of the 

 original stock whose hatching date is unknown were used in decreasing numbers as breeders, 

 which accounts for the small number of birds whose mean age at first egg is given. 



