66 



BOTANY OF THE LIVING PLANT 



it sometimes projects, or lies about level with the^general surface. 

 But in plants of dry climates it is apt to be sunk inwards. This 



FIG. 49. 



Stoma of Aloe depressed below the well-developed epidermis. The well -developed 

 cuticle is shown black. ( x 300.) F. O. B. 



is seen in slight degree in Narcissus (Fig. 48), but more distinctly 

 in Aloe (Fig. 49), a succulent plant with strongly cuticularised 



FIG. 50. 



Part of a transverse section of the xerophytic leaf of Hakea, showing a stoma 

 greatly depressed below the well-developed, and cuticularised epidermis, which is 

 propped out by thick-walled sclerotic cells. ( x 150.) F. O. B. 



epidermis. The stomata themselves are of the same type as Narcissi 

 but seated at the bottom of deep pits. A more extreme case is seen 



