4'08 TEXTBOOK OF BOTANY 



bearing leaves in 70 per cent alcohol or in 4 per cent formalin for the 

 study of the spore sacs and spores. The sexual plants may be obtained 

 by sowing spores in late summer or fall upon damp soil, sand, peat, or 

 sphagnum, which should first be sterilized by heating in an oven, if 

 possible, and after the sowing kept moist (but not wet). It is best to 

 sow the spores of several species, since there are great differences in 

 germinating power. Germination may require several weeks, or in the 

 case of some species several months. Sexual plants can also be ob- 

 tained from dealers in botanical supplies. 



1. What are the parts of a fern plant? What is their relation 

 to one another ? Which are the longer-lived parts ? How does 

 the stem branch ? Are all parts of the stem alive ? 



2. Can you find the growing end of the stem or of a branch? 

 What parts do you find at or near the growing end ? 



3. Cut across a stem between the points where two leaves 

 are given off. Study the cut surface of the stem with a hand 

 lens and sketch it. What different tissues can you make out? 

 How many vascular bundles are present ? Are they of the same 

 size? 



4. Where are the roots borne? Where are the youngest roots? 

 What is the shape of a root ? Its length ? Does it branch ? 



5. Where are the younger leaves to be found? What is the 

 appearance of the youngest leaf you can find ? How do the leaves 

 change as they grow older? Are there portions of dead leaves still 

 attached to the stem? 



6. What are the parts of a full-grown leaf? Does it bear hairs 

 or scales? If so, where? Describe the structure of the leaf -blade. 

 Draw one of the smallest divisions of a leaf, showing the arrange- 

 ment of the veins. 



7. Peel off a portion of the epidermis (outer layer of cells) from 

 the lower surface of the leaf and examine it under the microscope. 

 Do you find air-pores? Are they few or many? Do the guard 

 cells differ from the other cells of the epidermis in shape, size, or 

 color ? Draw an air-pore with a few of the neighboring cells. 



8. Where .are the spore sacs borne? Are they single or in 

 groups? How are they protected? Examine and draw a spore 

 sac. What are its parts? By alternately moistening and drying 

 a ripe spore sac, try to induce it to open under a microscope and to 



