Things that grow in the dark

Little one's school project involved three pots with cucumber seeds, one to be placed where there's warm and lots of light, one where it's dark and one where it's cold. The two weeks' results:
in Pot One there is this lovely plump plant baby growing;
in Pot Two there are two long and skinny stalks with tiny leaves on top;
in Pot Three there's no sign of life yet.

I feel so sorry for the Pot Two residents that the urge to sneak that pot out into the light grows stronger every day.