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,
Equus (play) by critics and audiences alike. Broadway World called the production 'dark, daunting and sensual' and commending its 'stellar cast'. Houston Press said it was 'astonishingly good... a must see' while Culturemap listed the show as one of the hottest shows of the year. Equus (play) Equus is a play by Peter Shaffer written in 1973, telling the story of a psychiatrist who attempts to treat a young man who has a pathological religious fascination with horses. Shaffer was inspired to write "Equus" when he heard of a crime involving a 17-year-old who blinded six horses in a small town near