56 0U7'LINES OF PLANT LIFE. 



II. The Sporophyte. 



Taking the underground parts in a dish of water, observe 



I. The slender wire-like roots. How are they branched ? (^ 83 ff.) 

 Where are they attached to the stem ? Trace an unbroken one to the tip. 

 The following points can only be seen on roots carefully gathered and 

 cleaned. What difference of color near tip ? Can you find many fine 

 Xz.-a^ti. root hairs ? Where present ? Where absent? (T[ 73.) 



Cut a transverse section of an old root, mount and observe 



3. The outer brown mechanical tissues (also used for storage). (^ 78.) 



4. The central whitish tissue, chiefly the stele, in which the visible 

 openings are the larger vessels. (^ 75.) 



5. In what position does the stem naturally stand ? Observe its occa- 

 sional branching (1[ 89) ; the surface covered with chaffy scales; the grow- 

 ing apex and dying hase. 



6. Its nodes and internodes ; the nodes are indicated by the attachment 

 of a single leaf at each ; the internodes are the intervals between the nodes. 

 How are the leaves placed? (^ 104.) 



Cut a transverse section of the stem and observe 



7. The outer brown mechanical tissues (also used for storage). '{^ 

 108.) 



8. The circular, oval, or C-shaped white tissues, most of which belong 

 to the stele. Trace the course of the stele through at least two internodes 

 by cutting a series of rather thick (I mm.) sections, observing the mode 

 in which the stele branches to pass out into a leaf. Cut also a longitudinal 

 section through the base of a leaf stalk and trace course of stele. (^ 

 109.) 



Taking a perfect leaf, dried under pressure, observe 



9. The stalk or petiole, with its branches. Note the mode of branch- 

 ing; the petiole divides into two equal divergent branches; each of these 

 forks, one branch carrying leaflets while the other again forks, and so on. 

 (11 126, 128.) 



10. The hardness of the mechanical tissues at surface of polished petiole. 



II. The leaflets. Note (a) shape as to outline and margin, comparing 

 basal, median, and terminal leaflets of any branch; [b] the veins, con- 

 taining branches of the stele; (f) the green tissues between the veins (Tf 

 127.) 



12. Demonstration. Strip off a bit of epidermis, mount and show (a) 

 the irregular form of epidermal cells; (b) the intercellular openings with 

 guard cells (stomata). (1]" 137.) 



13. At the edges of the leaflets on the under side crescentic brown spots, 

 clusters of spore cases. (1[ 275, figs. 149, 150.) 



