The theme of that poem is destructive potential of hatred and desire
Gandalf gets Beorn to shelter thirteen dwarves by bringing them in two by two while he tells an exciting story. ... the mention of the dwarves being attacked by Goblins eventually interests about the dwarves. Beorn doesn't like Goblins or the wolves.
Vestigial usually refers to traits which over evolution have lost their main function and are less useful than they once were.
In number one Hunter means that he thinks the teeth were from the ancestor whale shark but are now useless or nearly useless to the current whale shark.
Anne Sullivan, while describing her struggle to work with a young Helen Keller, wrote, "...the more I think, the more certain I am that obedience is the gateway through which knowledge, yes, and love, too, enters the mind of the child."
