THE FLOWERLESS PLANTS. 



35 



zomes of the different specimens. Cut transversely across 

 each rhizome and examine the cut end with a magnifier. 

 Make a sketch of each. The arrangement of the bundles 

 of woody fibers, fibrovascular bundles, and the bundles of 

 dark colored hardened 

 woody tissue, scleren- 

 chyma, form character- 

 istic figures in the 

 cross sections. 



2. Examine the leaf 

 or frond of an Aspidium 

 Fern. It is supported 

 by the stipe. It is com- 

 pound, the pinnae, branch- 

 ing off from the rhachis 

 or backbone of the 

 frond, these in turn be- 

 ing divided into pin- FIG. 14. Vertical section of stipe of Cin- 

 nules ' in some Species namon Fern, Osmunda cinnamomea, 



showing the fibrovascular bundle, F, in 

 there are Still lUrtlier longitudinal section, (x 35.) 



divisions. 



Make a sketch of the entire frond, showing the vena- 

 tion on some of the pinnules. Is the leaf netted- veined or 

 parallel-veined ? Draw the back of one pinna, showing 

 the arrangement of the fruit dots or sori. Cut across 

 the stipe and examine the cut end with a magnifier. 

 Repeat these observations with a frond of Adiantum. 

 In Aspidium and Adiantum do all of the fronds bear 

 sori ? How is it with the other available species of 

 Ferns? Find fruiting forms of as many other Ferns 

 as possible, and make a comparison of the manners in 

 which the sori are borne. Are they covered with a dis- 

 tinct indusium, as in the Aspidium, or is the indusium 

 formed by the folding back of the edge of the leaf, as in 

 Adiantum ? Is the indusium lacking in any specimens ? 



