William Tegetmeier (1816–1912)
‘Genealogy of cross-bred chickens’

These feathers from cross-bred chickens, showing plumage from birds of different ages, were sent to Darwin while he was seeking to understand the inheritance of sexual characteristics. He published his conclusions in Descent of man (1871): ‘With the breeds of the Fowl the inheritance of various characters by one sex or by both sexes, seems generally determined by the period at which such characters are developed. Thus in all the many breeds in which the adult male differs greatly in colour from the female and from the adult male parent-species, he differs from the young male…’ (Descent of man, 1: 294)

MS DAR 142: 52