EXPLANATION OP THE PLATES. XX1U 



Fig. 13. One of the above-mentioned diaphragms separated , a. the 

 cellular sides of the vacuity ; b. the diaphragm, which is 

 slightly convex on the exposed surface, (p. 596). 



14. Portion of the cuticle of the leaf of Zea Mays: a. a. the 



cuticular or pneumatic pores ; b. b. the lymphatic vessels, 

 (p. 605). 



15. Structure of the cuticular pore in the leaf of Zea Mays. 



16. Transverse slice of a portion of the leaf of Hoya carnosa: 



a. the cutis of the superior, 6. that of the inferior surface, 

 (p. 590). 



