Puzzling out Hrabanus Maurus' Encyclopedia: A Manuscript Tale

When searching for manuscripts of Hrabanus Maurus' medieval encyclopedia De rerum naturis (On the Natures of Things) in the database Digital Scriptorium, I came across a leaf fragment held at Columbia University Libraries (Plimpton MS 128 ) which, in terms of its handwriting and style of illumination, was clearly connected to a leaf fragment held at the University of Michigan Library (Mich. Ms. f. 14).