THE WALLFLOWER 41 



e. Protoplasmic Movements 



A good example of protoplasmic movement is 

 afforded by the cells of the leaf of the American Water- 

 weed (Elodea canadensis), a transatlantic alien, which 

 is a great deal too common in our rivers and canals. 



FIG. 18. Cells from the endosperm of the seed of a Palm 

 (Bentinclria), showing the fine strands of protoplasm con- 

 necting the cells. Some (w) pass through the full 

 thickness of the wall, others (p) through the thin places 

 or pits. (After Gardiner.) Magnified 550. 



In order to see the movements of the protoplasm, a 

 young leaf is removed from the stem and examined in 

 water under the microscope. The movements may 

 not begin at once ; in cold weather they are especially 

 sluggish, but can be hurried on by gently warming the 

 slide with the leaf upon it over hot water. 



