■1. 



Fi :• 11. A > j'luisvorcG section of loci v,ho\'fiYi(^ still o- 

 sejTyiient'j. 



Fi;:. 12. Tiie zvsao r/oill older. xTOO. 



Fig. 13. TrtmsYGr^o -.oct^-n of leMf aftn-,- five section 

 v/Lills are foiTned. x7r)0. 



Fif^. 14. Trimsyerso section of :.\ petiole showing cm 

 ultimate inarr^in.l cell df the fifLn gracie. xVOO, 



Fig. 15, Similar sc:ction she -ing the ultimate marginal 

 cell of the sixth, grade, x 7C0. 



Fig, lil. Trtmsverse section of petiole in v;hich opi- 

 deiTnal cind Iiypodermal layers are completed cmd the partition 

 colls a:'C; nearl;; ready to cut of cros'.; pai'i-ition cells. 



x7oO. 



Fig. 17. Part of similar sccbion o.^ a still older 

 petiole. x400. 



Fig, IS, The stime section of a Soiii older petiole.x400. 



Fig. 19. Trt'jisvorse section of a nearly m,.tiire petioU. . 

 x.'O. 



Plate II . 



Fig. r:0. Part of ti-ansverse section of the sane pei 

 x300. 



Fig. 21. Tcmgential section of petiole sliovdnr th' 

 ;,ir ciuials I'lV- f ns. x';00. 



