I first spotted the image in the early textbooks of George W. Hunter, including A Civic Biology (1914), famous as the central exhibit in the Scopes trial. It stood out because it gave off such a curiously anachronistic aura in Hunter’s otherwise proudly “modern” works. Once struck, I started seeing the thing everywhere. I found variations in at least eight competing twentieth century American high school textbooks. And moving back in time, I uncovered dozens of instances published in the century prior.