The Molting of Fowls. 397 



Relative influence of time of molt one season on time of molt the following 



season. 



The question naturally arises whether hens tend to molt at the same 

 season in successive years. Careful observations of trap-nested hens 

 (one-year-olds) in the molting seasons of 1906 and 1907 showed that, 

 of both flocks (65 hens), 78.5 per cent molted at practically the same 

 season in two successive years. Where the hens had been fed in the 

 same way during the two years, 87.5 per cent molted at about the same 

 time. The hens which had been starved one year to hasten the molt, 

 and fed after the usual method the next year, did not molt as early the 

 second year as the first. In other words, the so-called "forced molt" 

 held good for only one season, and possibly delayed molting somewhat 

 the second year. 



It is apparent from the plotted curves of percentages of (A) egg- 

 production and (B) hens molting, that early molting causes early decHne 

 in the production and that late molting tends to postpone the time of 

 decline (Fig. 21). This figure also serves to indicate that the older 

 fowls have a tendency to molt later than the younger. Notice also that 

 the fed flocks began to molt considerably later during their second year, 

 1907, than they did during their first year, 1906. Inasmuch as the 

 same tendency was observed with both starved and fed flocks it would 

 appear that the lateness of molting in the second year might be due 

 more to the age of the fowls than to the methods of feeding. 



Forty-five per cent of the starved hens began to lay at about the same 

 time in 1907 as they did in 1906. With the fed hens it was about sixty- 

 three percent. In 1906 (the year of starving) seventy-nine percent of 

 the starved hens began laying earlier than in 1907, and the entire starved 

 flock averaged 24 days earlier in 1906 (Fig. 21). 



Hens that shed late take less time to molt. 



In these observations it was found that the hens, from all pens, which 

 began to molt before September 15th, averaged 108 days molting, 

 while those which began after that date molted in 81 days. This con- 

 dition seems, in the case of the one-year-olds, to be modified by the 

 method of feeding. Of the fed one-year-olds, the hens which molted 

 early averaged 35 days longer in molting than those which molted later; 

 but of the starved one-year-olds, those which shed early averaged two 

 days less in molting than those which shed later. The eight hens, from 

 both of these pens, which began molt after October first averaged 82 

 days molting. In every case where the molt appeared to be uninfluenced 



