THE FLOWERING PLANTS. 



29 



of fibers wound in spi- 

 rals ; also for vessels 

 whose walls are sup- 

 ported by rings at in- 

 tervals. With a little 

 patience all of these 

 vessels may be found. 

 These vessels constitute 

 the principal portions of 

 the wood of the stem. 

 The markings observed 

 are thickenings to give 

 strength to the cell walls 

 and to the stem. 



FIG. 9. Epidermal cells 

 and storaata of Corn. 



FIG. 8. Fibrovascular bundle of Indian 

 Corn, Zea mays. Transverse section, as 

 seen under high power. O, P t P, cells 

 of the ground parenchyma. The tissue 

 represented by thick dark walled cells is 

 the bundle sheath ; E, E, pitted vessels ; 

 F, an annular vessel; A, spiral vessel: 

 L, empty space produced by the tearing 

 apart of the tissues in consequence of 

 rapid growl h ; H, II, sieve tissue consti- 

 tuting the bast or phloem portions of the 

 bundle ; E, E, A, and F are the main ves- 

 sels of the xylem. The lower part of the 

 figure was situated towards the center of 

 the stem. (X 500.) 



4. Examine the veining in the 

 leaves of Corn, Lilies, Palms, 

 Canna, Orchids, Wandering Jew 

 (Tradescantia), and various 

 grasses. Represent by drawings 

 as many types of parallel veining 

 veins are characteristic of the 



as you find. Parallel 

 Monocotyledons. 



5. Examine under the compound microscope bits of the 

 epidermis from both surfaces of each of the above leaves for 

 stomata. On which side of the leaf are they more abun- 



