No text, but a visual code

[Linda]

I believe the colours in quire 13 do in fact show differences of water, blue for fresh, including lakes, rivers, runoff from mountains and originating in clouds, green for saltwater lakes and seas. I also do not see anything that points to it being sap, you would think if that were the case there would be an example attached to a plant drawing to signify this, yet there is only one plant in quire 13, and i think its use there is symbolic, not botanical, plus there is no sap nor water drawn in conjunction with that one either.