Hiram Bingham was told of a plant whose juices softened rock so that the surfaces would join perfectly. There are reports of such a plant, including this one by one of the early Spanish Chroniclers: While encamped by a rocky river, he watched a bird with a leaf in its beak light on a rock, lay down the leaf and peck at it. The next day the bird returned. By then there was a concavity where the leaf had been. By this method the bird created a drinking cup to catch the splashing waters of the river. Considering the fact that lichen softens stone to attach its roots, and considering the ongoing extinction of plant species, perhaps this isn't really such a far-fetched notion.