82 



THE PLANT CELL. 



Fig. 67. — a, Raphides in a cell of the stem of Dracceiia ; these crystals are 

 large spindle-shaped ones, h, A bundle of small needle-shaped 

 raphides in a cell of Dracaena, c. Clustered crystals from the leaf of 

 Begonia. d, A quadratic crystal from Begonia leaf. All 

 crystals are composed of calcium oxalate, Ca(C03)2. 



