Horse outward similarity is an unreliable measure of relatedness. Besides the horse, there are six other species of genus "Equus" in the Equidae family. These are the ass or donkey, "Equus asinus"; the mountain zebra, "Equus zebra"; plains zebra, "Equus quagga"; Grévy's zebra, "Equus grevyi"; the kiang, "Equus kiang"; and the onager, "Equus hemionus". Horses can crossbreed with other members of their genus. The most common hybrid is the mule, a cross between a "jack" (male donkey) and a mare. A related hybrid, a hinny, is a cross between a stallion and a jenny (female donkey). Other hybrids include the zorse,
The Adventures of a Donkey Staples - Jemmy's fifth owner Juba - Donkey who shares Mr Staples' shed with Jemmy and Balaam Earl of Hampton - Jemmy's sixth owner Lady Hampton - Earl of Hampton's wife Lady Harriet - Earl and Lady Hampton's daughter Master Hubert - Lady Harriet's brother Mr Maxwell - Bricklayer; hires Jemmy from Mrs Staples for two months Thomas - Mr Staples' son Cousin Smith - Mr Staples cousin The Sandman - Jemmy's seventh owner Mrs Ellis - Laundress who cares for Jemmy Mr Turner - Jemmy's eighth owner Maria Turner - Mr Turner's eldest daughter Emma Turner - Mr Turner's