ECOLOGY 



what should have been the underside was brought uppermost 

 and facing the sun. The result was that the palisade tissue was 

 developed on the side toward the light, that is, on the mor- 

 phological underside. 



FIG. 43. Leaves of the sensitive pea closed. In this case the leaves close when 

 touched. No explanation for this habit is known. 



206. The position taken by the chloroplast in the cells is 

 also determined by the intensity of the light. In bright light 



