204 PRACTICAL LESSONS IN SCIENCE. 



masses of sporangia called sori. The plant should be gathered 

 for study some time in August, and the fresh specimen may be 

 studied, or the stem and roots may be preserved in alcohol, and 

 the stipe and frond dried in a plant press or book, and the study 

 made at some other time. 



With the complete plant in hand, notice the dark brown stem, 

 from which the slender branching roots arise, then the leaf with 

 its polished stipe and green leaflets, and lastly the hairs on the 

 roots, the scales on the rhizome, and the sori on the leaflets, which 

 together are called trichomes. Each of these parts is worthy of 

 study. Notice the shape, size and surface of the rhizome, its 

 growing apex and dying base. Those places on the rhizome from 

 which leaves grow are called nodes and the intervals between the 

 nodes are the internodes. Examine the buds at and near the 

 growing end of the rhizome; some show rudimentary leaves with 

 coiled stalks, and one or more are simply continuations of the 

 stem. Notice the arrangement of the buds and leaves on the 

 rhizome. 



Crush a portion of the rhizome and then pick out the whit- 

 ish bands of vascular tissue, trace this tissue into buds, leaves 

 and branches of the stem. Make cross sections of the rhizome at 

 the nodes and between them and note the outer ring of brown 

 tissue, and the somewhat horseshoe-shaped whitish mass, the 

 vascular bundle; examine several sections so as to get a clear idea 

 of the position of this tissue in the internodes, at the nodes and 

 other places. Split a portion of the rhizome with a sharp knife 

 and examine the sections carefully. Notice the shape of the roots, 

 their mode of branching, the root hairs, the growing tip, make a 

 cross section and look for the vascular bundle. 



Note the color, form and mode of branching of the stipe .or 

 rachis of the leaf, trace the vascular tissue into branches and 

 smaller divisions of the rachis. Make cross sections at different 

 places along the rachis, and compare with sections of the rhizome. 

 Study the shape of the leaflets and compare the one at the apex 

 with others on the seconday branches. Note the surface, texture, 

 color and framework or veins of the leaflet. 



