[Mithadan]

Setting aside the bridge this chapter presents to the Lord of the Rings, the most significant aspect was that Bilbo learned to be self-sufficient. He did not rely upon Gandalf or the Dwarves to rescue him. Instead, he managed to rescue himself. This is a significant step in the development of Bilbo. After his escape from the caverns under the Misty Mountains, he achieves the self confidence and self reliance to chase away the spiders of Mirkwood and rescue the Dwarves from the dungeons of the Wood Elves. This leads to Bilbo's willingness to enter the Lonely Mountain by himself and later strike the bargain regarding the Arkenstone.

In short, he becomes brave. He becomes a hero rather than comic relief. And in doing so, The Hobbit begins the transition from a children's tale to part of the larger history of Middle Earth. So this chapter could also be considered a significant step in the evolution of Tolkien as an author as well.