no joke WTF?? i want to know

I have been wondering this for a long time, and i hope that i am not the only one, but where exactly do the random parts of the book come from. These parts just appear in between major events and the actual story itself and just disrupts my whole pattern of reading. I can't help but be confused when there is a transition from a parade scene to deformed mollusks. Obviously the mollusks were being compared to people, but why is that part even there. It goes from a nice little story about a scythe wielding crazy and a candy chunking mob into a hardly connected ramblings on genetics and the rights of mollusks.
I know one of the big parts of this book is the whole "stream of consciousness" thing, but who's stream are we following. Is it of one of the authors just trying to fill up space in the book? Or is it used to show different parts and pieces of flatland that wouldn't fit easily or interestingly into the story? Or is it Square who is thinking all of these things? is he often lost in his own mind pretending to be thinking about his book ( or really thinking about the book) and we just get to see a conglomeration of his thoughts? Personally that is what i think. i believe these interruptions are just Square's thoughts about things. They are in places in some way connected to what he had been saying in his little side notes during the actual story. like on page 112, the side bar comments on how the language of the bankers is more important than the messages of previous civilizations. this correlates to the discussion of the randomness about the dying of languages.
Does that sound right at all??

PS if this sounds rushed or doesn't make sense it is because i have to run off to work and don't really have time to proof read. Sorry