In 1820, George Douglas, 16th Earl of Morton, reported to the Royal Society that he had bred a chestnut mare with a wild quagga stallion, and when he later bred the same mare with a black stallion, the offspring had striped markings and stiff manes, like the quagga. This case became the most widely cited example of the theory of telegony (ie that a female's first mate may influence the future offspring from different sires). Although it had received some challenges from the 1860s, this theory did not fall out of favour until the turn of the twentieth century. Ewart's experiments aimed to repeat the conditions of Lord Morton's experiment as closely as possible by crossbreeding horses with zebras (quaggas being by then extinct). Of the sixteen hybrid offspring produced by different matings, no positive evidence of telegony was found.