Memento Mori

The traditional Aldine title page is understated, disguising it as a text page almost. In our copy, two large letters, red and blue, make use of the typographical space afforded by the simple title page, largely empty and set in mere text capitals.

Title page with rubricated MM 

 The lettering in blue and red is part of the rubrication which is present throughout the book, and conducted in the same Gothic style of  lettering. The meaning of these two letters liberally placed on the title is not immediately evident, but one possibility is that they stand here as a Christian reminder of mortality: Memento Mori. This motto is especially poignant in light of the luxurious manner in which
the book in question has been elaborated. As if to say, don't be blinded by the beauty and luxury of this book, the vanity of earthly riches - remember your own mortality. An alternative reading could relate this decoration to the first word of Pliny's text: "Mundum", which is highlighted with an illuminated initial in this copy, (fol 1) the only instance of this enhanced technique.
The style of the red and blue rubrication is evident throughout the volume, marking printed initials, chapter headings, page headers in vivid color. Here is a sample page, talking about bees and wasps, which demonstrates the program, and also gives a good view of the italic type the book is set in.

De continendis apibus; De Vespis