PLATE XXXVIII. 



Fig. 8. Cross section of collenchyma rib. x 255. 



Fig. 9. Longitudinal section of collenchyma rib. x 165. a, collen- 

 chyma cells; 6, parenchyma cells. 



Fig. 10. Cross section of stoma, x 285. 



Pigs. 11 and 12. Trichomes from stem, x 55. a, basil cell. 



Fig. 13. Epidermis from stem, x 183. a, epidermal cells above col- 

 lenchyma ridge; 6, epidermal cells in channels. 



Fig. 14. Longitudinal section of stem, x 165. a, guard cell of stoma; 

 b, palisade parenchyma; c, short chloroplast-bearing cells; d, paren- 

 chyma cell of an aqueous tissue. 



