Slide showing hierarchical chart of the crossing of black rosecomb and white singlecomb hens/cocks. Slide shows hierarchical chart of the crossing of black rosecomb and white singlecomb hens/cocks. There are three levels labelled 'P1', 'F1' and 'F2'; 'P1' shows the white singlecomb male and black rosecomb female; 'F1' shows the creation of a white rosecomb; 'F2' shows results 'g' (white rosecomb); '3' (white singlecomb); '3' (black rosecomb) and 'l' (black singlecomb). Title below images reads 'Fig. 10 - Black Rosecomb x White Singlecomb'. Label in upper left corner reads 'Makers Newton and Co, 43 Museum Street, London WC1.' Late 19th to early 20th century