Plate VI 



PLATE VI 



"j'ig-ure 25. ^Photomicrograph of longitudinal section through stem 

 apex ; showing growing point and leaves in successive stages 

 of development, similarly as in PI. I, tig. 1. X 40. 



Figure 26. — Photomicrograph of apical portion of leaf, not quite mat- 

 ure; sliowing marginal teeth. X 35. 



figure 27,— Photomicrograph of cross section of root; showing- 

 epidermis, exodermis, cortex, endodermis and axial vascular 

 bundle. X 60. 



Figure 28. — Photomicrograph of j'oung" leaves surrounding growing- 

 point, dissected from living specimen, x 35. 



Figure 39. — Photomicrograph of portion of epidermis near apex of 

 root; showing trichoblasts (the darkly stained cells). X 40. 



Figure 30. — Photomicrograph of surface of leaf treated with a five 

 per cent solution of potassium hydroxide ; showing epidermal 

 secretion cells and central vascular bundle. The marginal teeth 

 have been worn off. X 30. 



"Figure 31. — Photomicrograph of a cross section through a node of 

 the stem showing the origin of a single root — the typical con- 

 dition. In this figure the meristematic la3^ers at the growing 

 point of the root are clearl}' defined. X 35. 



Figures 32 and 33.— Photomicrographs of adjoining portions of a 

 nearly median longitudinal section through the root apex, show- 

 ing trichoblasts. (The root cap was slightlj'^ separated from the 

 growing-point in preparation.) x 50. 



Figure 34.— Photomicrograph of cross section of yoimg peduncle, 

 showing axial bundle, lacunae in cortex, &c. X 35. 



32 



33 



