The IMolting (jf Fowls. 



Z7^ 



Housing. 



In pens 5 and 8 there were respectively 40 and 38 three-year-old hens, 

 in pens 19 and 22, there were 40 and 42 two-year-old hens, and in pens 

 24 and 25, there were 34 one-year-old hens each. The flocks in each set 

 of pens were divided as near equally as possible in regard to weight and 

 vigor. The experiment was continued until November 8, 1907, covering 

 a period of 455 days. This time was divided into fifteen 28 day periods 



Fig. II. — New and old feathers, i, new back-feather , 2, new fluff -feather; 3, worn 

 back-feather , 4, worn fluff -feather, a, tip, b, web, c, down; d, ihaft, e, bract. 



and one 35 day period. Males were kept in pens 24 and 25 throughout 

 the entire experiment, and in the other pens during the winter and early 

 summer only. The hens in pens 24 and 25 (one-year-olds) were trap- 

 nested, the records having been begun January 24, 1906. 



Flocks 5 and 8 were kept in the same house. Each of these pens contained 

 2.25 square feet floor space; .13 square feet cloth or glass surface; and 17.5 cubic 

 feet air space per hen. Flocks 19 and 22 were in the same house m similar pens 

 each containing 2 square feet floor space and 1.2 square feet cloth or glass surface 



per fowi, Pen ig having 18.2 cubic feet, and Pen 22, 15.4 cubic feet, of air space 

 per fowl, in the roosting room. (Computed un a basis of the inimber of hens in 



