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,
George Africanus and labourer as well. Following his death in 1834, his wife Esther remained in the house and continued to run the family business. After she died on 12 May 1853, a notice appeared in the "Nottingham Review", stating: "Yesterday (Thursday), aged 85 years, Mrs. Africanus, for upwards of sixty years proprietor of the Servants' Register Office in Chandlers Lane." If this account is correct, then Ester ran the Servants' Register Office on Chandler’s lane from at least 1793. Africanus bought 28 Chandlers Lane and adjoining properties in Bluchers Yard for £380 on 24 October 1829. Africanus and his wife had