Hey man, just from looking at this picture and the other pictures from your diary, that's as healthy as the leaf can look in my eyes. I also don't really understand what you mean by bottom? The point where the leaf-fingers connect is called rachis as far as I know (Just dropping some nerdy knowledge here, please don't kill me if I'm wrong :D) But in all honesty, the plants look extremely happy man, don't worry too much. Oh and btw, like
@FREE_HONGKONG mentioned, definitely top them, it'll work wonders.
BTW I know from past experience that the older the leaves get, the more of a "papery" and fairly rough feel they get. Thats apparently completely normal ;)
Love and peace :)