Two of my favorite things: trees and shakespeare

We recently made nature journals with help from Donna Young at http://www.donnayoung.org/. Yesterday, the kids picked leaves and did a page describing a tree. We are pressing the leaves, and will insert them in our journal. When looking for a heavy book to press them in, I decided my Pelican Shakepeare was just the right heft. So we are pressing our leaves in the midst of Julius Ceasar, which we are studying for history. Does this count as a unit study?