Pi A evel 
Figure 25.—Photomicrograph of longitudinal section through stem 
apex; showing growing point and leaves in successive stages 
of development, similarly as in Pl. I, fig. 1. >< 40. 
Figure 26.—Photomicrograph of apical portion of leat, not quite mat- 
ure; showing marginal teeth. >< 35. 
Figure 27.—Photomicrograph of cross section of root; showing 
epidermis, exodermis, cortex, endodermis and axial vascular 
bundle. >< 60. 
Figure 28.—Photomicrograph of young leaves surrounding growing- 
2 
point, dissected from living specimen. >< _ 36. 
Figure 29.—Photomicrograph of portion of epidermis near apex of 
root; showing trichoblasts (the darkly stained cells). >< 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 
havé been worn off. >< 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 layers at the growing 
point of the root are clearly defined. > 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 slightly separated from the 
growing-point in preparation.) >< 50. 
Figure 34.—Photomicrograph of cross section of young peduncle, 
showing axial bundle, lacunae in cortex, &c. >< 38. 
