"It appears even that to these black elves in particular, i.e., mountain spirits, who in various ways came into contact with man, a distinct reverence was paid, a species of worship, traces of which lasted down to recent times. The clearest evidence of this is found in the Kormakssaga p. 216-8. The hill of the elves, like the altar of a god, is to be reddened with the blood of a slaughtered bull,…