An interesting observation on Quire 13

[ReneZ]

I've noticed this too, and if you think about it some more it's clear that it's not just the Bio section that is like this, but the entire manuscript.  The bifolios were never intended to be nested within one another.  Each one was intended to stand alone as its own "quire".

However not for the three pharma bifolios, judging from the containers.
The two nested bifolios 99-102 and 100-101 seem to be organised correctly. The only minor inconsistency is, that the first one on 99v has been drawn a bit more elaborately and could have been meant to be the first one, but there is no way to reorganise thefolios to make this work.

Most importantly, the transition from one style (2 or 3 cylindrical segments with diameters reducing from bottom to top) to another one (including narrow and tapered sections) occurs in the course of folio 102 (from recto to verso).
It continues that way on 88 recto, and here immediately (after the first one) another common change happens: from the second one onwards, all containers have lids. Before that, none of them has.

One other feature, whether they have feet or not, is alternating, though there are no feet on fols 100 and 101.
(Maybe someone is interested in doing some folding experiments and figure out the most logical total arrangement).

The main points is, however, that there is a continuous progression and the main changes do not happen on bifolio boundaries.