2Q4 



BOTANICAL GAZETT1 



[OCTOBER 



Fig. 20. — Solid protostele with detached tracheae, decurrent from root 

 which leaves stele immediately above. 



Fig. 21. — Enlarged xylem group just before medullation.* 



Fig. 22. — Early medullation and inclusion of first storage parenchyma 

 cells; eleventh trace. 



Fig. 23. — Twelfth trace and eighth root. 



Fig. 24. — Increase in storage parenchyma cells and medulla; ninth root. 



PLATE xxv 



Fig. 25. — Mesarch bundle in petiole of first leaf; X625. 



Fig. 26. — Transverse section of foot, showing closing of endodermis in 

 three-leaved stage; X88. 



Fig. 27. — Transverse section of abnormal tracheids; X625. 



Fig. 28. — Stele at time of departure of fifth trace, showing solid xylem 

 group and prominent sheath parenchyma; X300. 



Fig. 29. — Longitudinal section of tracheid in axial continuity with xylem 

 parenchyma cells; X300. 



Figs. 30, 31. — Sieve tubes with oblique terminal walls; X300. 



Fig. 32. — Stele immediately above foot; lateral embayment to right of 

 foot attachment and indention of stele to isolate first trace at left; X300. 



Fig. S3- — Normal endarch bundle of first trace; X88. 



Fig. 34. — Fifth leaf strand 2.25 mm. above origin; phloem encircles 

 xylem which shows adaxial embayment; X300. 



PLATE XXVI 



00 



Fig. 35. — Stem apical cell with leaf initial isolated at left; X 



Fig. 36. — Longitudinal view of stem apical cell; X575. 



Fig. 37. — Isolation of leaf initial from stem apical cell; X575. 



Figs. 38, 39. — Irregularity in segmentation of stem apical cell; X575. 



Fig. 40. — Abnormal meristem with apparently four initials; X3C0. 



Fig. 41. — Transverse view of normal stem apical cell; X129. 



Fig. 42. 



fungus; X625. 



Fig. 43. — Transverse section of normal root, showing diarch character; 

 X88. 



Fig. 44. — Transverse section of stem, showing at left a pericyclic intrusion 

 and strong development at edge of root attachment; X88. 



Fig. 45. — Longitudinal section of root apical initial in pericycle; X300. 



Fig. 46. — Irregular segmentation of root apical cell; X575. 



Fig. 47. — Transverse section of triangular-pyramidal root apical cell; 

 X300. 



Fig. 48.— Tangential section of stele, showing organization of root apex 

 in pericycle; X300. 



