National Geographic : 1957 Dec
© National Geographic Society + A Dash of Dye Inside Goose Eggs .. . Near the end of their four-week incubation period, a biologist swabs shells with alcohol, then injects dye. Harmless coloring spreads over the imprisoned embryos. A touch of collodion from the flask in foreground seals the puncture. All Kodachromes by John and Frank Craighead . . .Gives Goslings a Scarlet Hue 4 Normal yellow chicks huddle amiably with their bizarre broodmates. Once hatched, goslings cannot be dyed by dunking, for the oily down sheds dye like water. Weeks of spying on red, green, and blue goslings revealed movements and mortality.