SCOTS PINE. 



375 



(4) The sunken stomata, each stoma interrupting the 

 epidermis and hypodermis and having its two guard-cells 



Fig. 92. PINUS. One-half of a Transverse Section of a Foliage-leaf. 

 See 524. 



quite below the epidermis and above an air-cavity in tlje 

 niesophyll. 



