Following the "bifolio" thread for awhile, I just ran a study that indicates
a strong association between bifolio 21 and bifolio 23. That would be,
bf21= 41r,41v,48r,48v, and bf23= 43r,43v,46r,46v. These two bifolios share
84 words in common, one of the highest counts between bifolios in the herbal
section, and several of the words are unique to these two bifolios only.
Both are [hb] bifolios that appear to be out of place.
I was going through the images at the same time to look for Nick's "smudge"
evidence, and noticed something odd about the smudges at the tops of certain
folios. Like a water stain that changes shape as it soaks through pages,
the smudges do the same, leading me to think these are water damage of some
sort. Most seem to be in the right place, but some just don't add up.
I'd hate to jump to any conclusions on this without having others look at
the same progressions. I will however say that I would personally place the
smudges from bifolio 21 in a different order, and that order would probably
be somewhere in the proximity of bifolio 23.
Keep in mind that "water damage" is sheer speculation on my part and there
could be other reasonable explanations.