196 MAINE AGRICULTURAL EXPERIMENT STATION. I9II. 



or stimulated) process. The second or spring period (March i 

 to June i) is the natural laying period of the domestic fowl in 

 its normal reproductive cycle. The third (roughly June i to 

 September i) and fourth (roughly September i to October 31) 

 periods are not sharply separated from one another. The sum- 

 mer egg production represents in part a natural continuance of 

 the normal breeding season (rearing of a second brood by wild 

 G alius) and in part a stimulated process. This period is termi- 

 nated by the molt, which is the characteristic feature of the 

 fourth period. 



6. There is no evidence that the continue;! selection for 

 higher egg production practiced during the eight years covered 

 by the experiment j^roduced any increase whatever in the mean 

 egg production of any month in the year. On the contrary, the 

 mean production in all but two' of the months actually decreased 

 during the period of selection. 



7. So far as there was any change whatever in variability 

 in monthly egg production during the period when selective 

 breeding was practiced, this change was not in the direction of a 

 reduction as a result of the selection, but, on the contrary, there 

 was an actual increase in variability in all but one month of 

 the year, and here the platted variability line did not sensibly 

 deviate from the horizontal. 



8. The present statistics show no bad effect on egg produc- 

 tion in the winter months (November to March) of keeping 

 birds in large and crowded flocks (up to the limits included in 

 the present study). On the other hand, overcrowding tends 

 distinctly to lower summer (and to a smaller extent spring) 

 egg production. It is chiefly as a result of this effect on sum- 

 mer production that the mean annual production is lower in 

 the large flocks, as shown in Part I of this work (Bureau of 

 Animal Industry Bulletin no. Part I, pp. 58-61). 



9. The excess in relative variability of egg production of 

 the larger flocks (100 and 150 birds) over the smaller (50 and 

 100 birds) observed in the annual records (see Part I) is found 

 upon analysis to be on the whole fairly evenly distributed over 

 the whole year. In the period of the year in which there is the 

 heaviest production, such environmental differences as are im- 

 plied in the different flock sizes in the experiment do not 

 appreciably affect the relative variability of production. 



