The Genetic and the Operative Evidence Relating to Secondary Sexual Characters

"The Genetic and the Operative Evidence Relating to Secondary Sexual Characters" by T. H. Morgan is a detailed study on the heredity of secondary sexual characteristics in poultry, focusing on hen-feathering in Sebright bantams. The book explores the genetic factors influencing hen-feathering, with experiments involving castration of hen-feathered males to observe the transition to cock-feathering. The study also delves into the color inheritance in the cross between Sebright and Black-Breasted Game bantams. The F₁ and F₂ generations are analyzed, revealing the dominance of hen-feathering and the complexity of color patterns in the offspring. The book provides insights into the genetic basis of secondary sexual traits and the interplay of different factors in determining plumage characteristics in poultry.