When Science Attacks!

So last Friday, we put cress seeds on two wet paper towels in two petrie dishes and set one in the windowsill and one in a dark cupboard. The point of the exercise was supposed to be to demonstrate that plants need sunlight to sprout.

Only the sun coming through the window kept drying out the wet paper towel for the "good" petrie dish. I'd eventually remember it and rewet it, but the upshot is that the seed in the sunlight has done nothing, while the overachieving seed in the dark cupboard (where the paper towel stays damp much longer) is actually sprouting! (Pale albino sprouts, but still.)

So now the question is, do I switch the dishes to "prove" to Eric that yes, plants need sunlight to grow, or do I tell him that they really do despite the evidence of our little experiment?