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) this off when he hears the horses making noises in the stables beneath, which he decides is the reason for his inability to get an erection. Jill tries to ask Alan what the problem is, but he shouts at her to leave. After Jill dresses and walks out of the stables, the still nude Alan begs the horses for forgiveness, as he sees the horses as God-like figures. "Mine!...You're mine!...I am yours and you are mine!" cries Equus through Dysart's voice, but then he becomes threatening: "The Lord thy God is a jealous God," Equus/Dysart seethes, "He sees you, he