So now, when I think of this novel, I think of it as an evolved creature - there are sentences there that have survived from the beginning. They are like the sequences of valuable genes - the ones too useful to let go - and so persist through the generations in insect, reptile, mammal, man. Then, next to these conserved phrases, there are the newer sentences around them. Sometimes these have been rearranged and refined, but more often they have simply been chipped away like telomeres.
Added later: Probably my most pretentious post to date - but I am unrepentant.