Add a few drops of food coloring to each beaker. Place a celery stalk in one beaker, flowering leaf end up. Place a lettuce leaf in the other. Observe the water level over a day or two. Then, use the magnifying glass to observe the celery and lettuce.
Conclusions Consider the vascular structure of the celery and the lettuce.
The blue food coloring should reveal the plant's network of veins. Extension Ideas Try the procedure with a non-vascular plant, such as moss or fern.