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THE AMEBIC AN NATURALIST [Vol. LII 



after its middle, the rate of decline being much greater 

 than for the Barred Plymouth Rocks. 



The summer period may be considered to be July, 

 August and September. Practically all the birds of the 

 flock are laying in broody cycles with egg production re- 

 maining at approximately a constant level, while consid- 

 erable partial moulting is going on. It passes gradually 

 into the fall period which is characterized chiefly by the 

 cessation of egg production— usually coinciding with a 

 broody period— and the onset of the fall moult together 

 with some slowing in rate of production of those birds 

 that are laying. Biologically the fall period overlaps the 

 calendar year since it may extend into December. The 

 question of egg production in the fall, at the end of the 

 pullet year, is on rather a different basis from that of the 

 other seasons of the year. The egg producing mechanism 

 of the hen seems to be in a peculiarly unstable condition 

 and unless great care is exercised may cease functioning 

 in response to slight adversities in environment. Some 

 hens, however, and this is really the important point, con- 

 tinue to lay throughout the fall months with the same 

 regularity they exhibited in the spring. This affords us 

 an opportunity to build up a strain of birds that will be 

 persistent layers throughout the year. 



Thus, persistency in egg production through the fall 

 months enters in as a factor in determining the total egg 

 production as has also been emphasized by Rice ('14). 

 Some birds cease laying relatively early in the fall, say 

 late in August or September; others, however, of the 

 same age, breeding, and under the same conditions, con- 

 tinue to lay all through the fall, at approximately the 

 same rate of production as during the summer months, 

 although the rate may fall off slightly. Now, these birds 

 will have quite a different total record from those that 

 stop early in the season and if one examines his records 

 he finds that while many persistent layers are also good 

 producers early in the season, nevertheless a great many 

 of the birds that were good layers during the winter are 



