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,
When a white horse is not a horse are one attribute; the ten thousand things are one horse. The "Mengzi" (6A4) notes that "bai" 白 "white" has different connotations whether we are using it to refer to a graying person (who is worthy of respect because of his age) or a white horse (which should be treated like any other animal): Mencius said, 'There is no difference between our pronouncing a white horse to be white and our pronouncing a white man to be white. But is there no difference between the regard with which we acknowledge the age of an old horse and that with which we