Fig. 1. Schematic representation of grafting experiments and resulting E15 quail-chick chimeras. Grafting of midbrain (control, A), cardiac (C) and trunk (E) dorsal neural tube tissues from stage 9-10 quail donors into stage 9 chick hosts results in highly pigmented E15 chimeras B, D and F, respectively. Cardiac neural crest chimeras form a distinct pigmented mass of cells (D, arrow) on the dorsal region of the cornea.