A Crow was filled with envy on seeing the beautiful white plumage of a Swan, and thought it was due to the water in which the Swan constantly bathed and swam. So he left the neighbourhood of the altars, where he got his living by picking up bits of the meat offered in sacrifice, and went and lived among the pools and streams. But though he bathed and washed his feathers many times a day, he didn't make them any whiter, and at last died of hunger into the bargain.
You may change your habits, but not your nature.
一只乌鸦看到天鹅美丽洁白的羽毛，非常嫉妒，觉得是因为天鹅经常在水中洗澡和游泳，所以才那么白。他本来一直生活在祭坛附近，以啄食祭坛上献祭的肉为生，为了变白，他离开了祭坛，去池塘和溪流边生活。尽管他一天洗好多次羽毛，但始终没有办法变白，而且最后还饿死了。
训诫：习惯可改，本性难变。