in the Evolution of Herbaceous Angio sperms. 533 
Fig. 17. Chelone , Herb. Tangential longitudinal section of slender herbaceous stem, showing 
entering leaf-trace and parenchyma of foliar gap. The confronting and flanking tissue is prosen- 
chymatous and 1 foliar storage tissue , is absent, x 50. 
Fig. 18. Asclepias , Herb. Tangential longitudinal section of node, showing entering leaf-trace 
and parenchyma of foliar gap. The vessels of the secondary xylem are curving around, and thus 
avoiding the leaf-trace, x 21. 
Fig. 19. Dillenia , Tree. Tangential longitudinal section of stem, showing entering leaf-trace 
and so-called foliar ray. The wide, very high ‘ flanking ’ rays are united for a considerable distance 
below the node by 1 confronting 1 parenchyma. The cells of the latter tissue are vertically elongated, 
x 42. 
Fig. 20. Same. At a lower level of the stem, showing flanking rays and dying out of con- 
fronting parenchyma, x 42. 
Fig. 21. Liriodendron , Tree. Tangential longitudinal section of stem, showing fusion of large, 
high flanking rays with the parenchyma of the foliar gap. x 31. 
Fig. 22. Acanthopanax, Tree. Tangential longitudinal section of stem, showing fusion of high 
flanking rays with parenchyma of foliar gap. x 33. 
