ANNUAL REPORT, 1938 93 



gence of about 2500 chicks. Observations were made during the hatching period 

 at 8-hour intervals beginning at the end of the twentieth day of incubation and 

 concluding when the chicks were taken from the incubator at the end of the 

 twenty-second day. The relation between time of emergence and sex, mortality 

 rate, body weight, and characters affecting fecundity are being studied. 



Relation of Plumage Color to Sex in Rhode Island Red Chicks. (F. A. Hays.) 

 A total of 6800 pedigreed Rhode Island Red Chicks have been described for brown 

 and black pigment spots or stripes on head, neck, and back. The value of pigment 

 areas for identifying sex at hatching and their relation to adult plumage color 

 are being studied. 



The Effectiveness of Selective Breeding to Reduce Mortality in Rhode Island 



Reds. (F. A. Hays.) Two lines have been developed by selective breeding: 

 one selected for low mortality in the laying houses, and the other for high mortality 

 in the laying houses. No other basis of selection was used in either line. In the 

 first three generations there was a significant difference in mortality rates of the 

 two lines. The fourth generation included too few birds to secure an accurate 

 figure on mortality rates in the two lines. The mean annual egg records were 

 213 and 170 respectively. 



Genetic Laws Governing the Inheritance of High Fecundity in Domestic 

 Fowl. (F. A. Hays and Ruby Sanborn.) Major objectives in this project are as 

 follows: (1) Developing a line genetically pure for sexual maturity in 180 to 215 

 days; (2) fixing high intensity so that winter clutch size will exceed 3; (3) elim- 

 inating all inherited winter pause; (4) eliminating the broody instinct; and (5) 

 fixing genetically high persistency. Along with the above characters, fertility, 

 hatchability, bod>' size, egg weight, comb type, feather color, and inherited fac- 

 tors affecting mortality rate are all being studied. 



The generation hatched in 1937 was particularly superior to previous genera- 

 tions in mortality rate in the laying houses and in freedom from broodiness. 

 Without culling, the mortality rate for a full year was 12.5 percent. Only 2.02 

 percent of the birds became broody in this generation. 



Genetic behavior of the characters being studied is constantly being checked 

 by crosses with outside stock. Results from these crosses are regularly checked 

 against the experimental line carried as such since 1913. 



Miscellaneous Studies. (F. A. Hays.) In addition to the above projects, a 

 number of other studies are being carried on. Among these are: Linkage relations 

 between genes for comb type, ear lobe color, and shank feathering; artificial in- 

 semination with old males in cold weather; and molting behavior at the end of 

 the first laying year and persistency of laying. 



SEED CONTROL SERVICE 

 Philip H. Smith in Charge 



Seed Inspection. (F. A. McLaughlin and Jessie L. Anderson.) From December 

 1, 1937 to December 1, 1938 the Seed Laboratory received and worked 2428 

 samples of seed, of which 1031 were collected by the State Commissioner of Agri- 

 culture and 1397 were sent in by seedsmen, farmers and the American Can 

 Company. 



Classification of these samples with the total number of tests involved is shown 

 in the following summary. It will be noted that the total number of tests required 

 for the 2428 samples was 3378; 859 for purity and 2519 for germination. 



