PLATE VIIJ.:22 
Fic. 39.—Surface view of leaf epidermis, upper surface: s, stoma; 
h, scar of trichome. 175. 
Fic. 40.—Surface view of leaf epidermis, under surface: s, stoma; 
h, sear of trichome. X 175. 
Fic. 41.—Surface view of leaf palisade. » 325. 
Fic. 42.—Cross section of a stoma, from a leaf cut longitudinally 
through the narrow diameter.  » 475. 
Fic. 43.—Cross section of the midvein of a leaf: ph, phloém; tra- 
cheids shown by stippling. x 325. 
Fic. 44.—Storage tracheids, from the ultimate ends of the veins of a 
leaf cut longitudinally through the narrow diameter. » 275. 
Fic. 45.—Storage tracheids from the ultimate end of a vein of a leaf 
eut longitudinally through the broad diameter. x 475. 
Fig. 46.—Spiral tracheid from a leaf. Xx 475. 
Fic. 47.—Trichomes from a leaf. x 175. 
Fic. 48.—Starch grains from the thin-walled parenchyma of a root. 
1325: 5 
Fic. 49.—Starech grains from the pith, medullary rays, pericycle, 
and primary cortex of a stem. » 325. 
Fig. 50.—Calcium oxalate crystals from the bark of a root. x 325. 
Fig. 51—Calcium oxalate crystals: a, from the cortex of stem; b, 
from a leaf. X 325. 
Fic. 52.—Calcium oxalate crystals from the pith of a stem. X 325. 
Fic. 53.—Crystals of calcium oxalate from the phloém of a stem. 
x 325. 
