LABORATORY AND FIELD WORK 409 



observe how the spores are thrown out. Examine some of the 

 spores. How do they compare with the spores of a moss ? 



9. Study the sexual plant of a fern. What is its shape ? How 

 large is it ? Which is its oldest part ? Its youngest part ? Where 

 are the rhizoids ? What is their worit ? 



10. Where are the antherids? The archegones? Are there 

 few or many of each? Draw a sexual plant as seen from the 

 under side, showing the positions of the rhizoids, antherids, and 

 archegones. Look for moving antherozoids ; they will break out 

 of the ripe antherids if the sexual plant is placed in water. 



11. If material is to be had, study a young asexual plant still 

 attached to the sexual plant. Can you find the primary leaf, 

 primary root, young stem, and foot? How does the primary leaf 

 compare with the leaves that are formed later ? 



12. Collect and make a list of the different kinds of ferns that you 

 find growing. In what kinds of places do the different species live ? 



13. Make another Est of such relatives of the ferns as you find — 

 water ferns, horse-tails, and club-mosses. 



Chapter XI 



1. Examine branches of a pine tree. Can you distinguish be- 

 tween long branches and spur branches? Do both kinds grow 

 longer from year to year? Do both grow thicker from year to 

 year? 



2. Find scale leaves and foliage leaves. Where is each borne? 

 How do they differ in size, shape, and color? Draw a twig, show- 

 ing both kinds of branches and both kinds of leaves. 



3. Can you determine by examining a long branch how much of 

 it has grown during the present year, and how much during each 

 previous year? What marks the end of each year's growth? 

 Where do new long branches start ? New spur branches ? 



4. Study a cross section cut through a long branch not far back 

 of the terminal bud. Can you distinguish epidermis, cortex, vas- 

 cular bundles, and pith? How are the vascular bundles arranged? 

 What are the parts of a vascular bundle ? In which part of a 

 bundle do you find the largest cells ? Draw a large enough portion 

 of the section to show the different tissues. 



