402 



Bulletin 258. 



that the demands of the body for nourishment from which to grow new 

 plumage is great. This is made apparent by the chemical composition 

 of the feathers, and also by the fact that only the strongest hens appear 

 to be able to produce feathers and eggs at the same time, even for a 

 short period. Table IX shows clearly by comparison the relative 

 amounts of nitrogen and mineral matter contained in the body, the 

 eggs and the feathers of the average 100 Leghorn fowls. 



It may be reasoned that it takes nearly a year to grow the body of a 

 hen, that young growing stock eat more per pound weight than mature 

 hens not in production, and that a year's production of eggs is estimated 

 to contain twice as much nitrogen as a hen's body. We also know that 



Fig. 21. — A comparison of per cent Molting and per cent Egg Production in two 

 successive years between flocks 24 (starved) and flock 25 (Jed). Trapnested hens. 

 Pens 24 starved and 25 fed, Periods of 7 days. 



=Starved flock. 



=Fed flock 



Note again the regularity with which the per cent egg production increases or decreases 

 as the per cent molting increases or decreases. Also observe that the molting was 

 later the second year than it xvas the first year, and that the starving process did 

 not materially influence the time of molt the follozving year. 



