One of the remarkable features of Tolkien’s sub-created world is its incredible diversity, a diversity that works in large part on account of the equally profound sense of a pervading unity behind the surface diversity. Tolkien doesn’t just give us things that are different, but things that feel like they somehow belong to each other in their difference.
This certainly isn’t the best or most representative example of this sort of thing, only the most recent illustration of it. Reading through “A Short Cut to Mushrooms,” I found myself wondering about Farmer Maggot’s choice of names for his dogs: Grip, Fang, and Wolf. Why these names? Who knows, but there is at least a possible relation between them. Grip, of course, is an action; fang is the instrument by which a certain kind of actor or agent, a wolf, performs the action of gripping. So, Grip, Fang, and Wolf–action, instrument, and agent. Just one example of Tolkien’s sub-creative achievement of unity amidst diversity.
The Flame Imperishable 
It seems like just the sort of thing a man in love with language would do, doesn’t it?
This is great.