CONTENTS 



Introduction .......... 3 



Objects of investigation ........ 5 



Data available ......... 5 



Part I. Egg Weight 



A. Winter egg weight ......... 6 



Correlation between winter and hatching-season egg weights . 6 



Correlation between winter and annual egg weights ... 8 



B. Hatching-season egg weight ...... 8 



Correlation between hatching-season and annual egg weights . 8 



Hatching-season egg weights of parents and daughters . 8 



C . Annual egg weight ......... 10 



Monthly mean egg weights ...... 10 



Progress in breeding for egg size . . .12 



D. Time to standard egg weight ....... 13 



Breeding value of fast, medium, and slow dams . . .14 



E. The inheritance of egg weight ...... 15 



Fixing large egg size in the flock .... .17 



Part II. External egg characters 



A. Shell texture 18 



Inheritance of shell texture . . . . . . 19 



B. Character of the ends of eggs ....... 20 



C. Shell porosity 21 



D. Egg shape 22 



E. Egg shell color 23 



Shell flecking .23 



Shades of egg shell color ...... 23 



Summary ........... 26 



References ........... 27 



