360 



FUNGI 



- I •.*•; \Wd - 



• 



Other common fungi are potato blight, red rust of wheat, 

 corn smut, which produces the black mass found in an 

 ear of corn, and the bracket fungi, which grow in large 



numbers on the trunks of trees 

 and whose hyphae cause the 

 death of the tree (Figures 381 

 and 382). 



The fungi used for food 

 are nourishing, but there is a 

 prejudice against their use be- 

 cause other fungi which re- 

 semble them closely are poison- 

 ous. As a matter of fact, it is 

 an easy task to learn to dis- 

 tinguish the edible from the 

 poisonous fungi. While the harmless fungi are now used 

 as food much more than formerly, only a few varieties are 

 raised for trade purposes (Figures 378-380). 



aX£3 



Figure 385. — Spores. 



Section through a leaf 

 injured by fungus. 



LABORATORY STUDY 



Wet a piece of bread, put a tumbler over it, and set it in a warm place 

 for three or four days. Examine without the microscope to get the 

 general appearance. With the microscope note (1) the clear, colorless 

 threads (hyphae) making up the mass ; (2) the groups of spore-bearing 

 bodies, black and round, on the ends of the upright stalks; (3) the spores 

 coming out of them. 



254. Lichens. — Lichens (H'kens) are grayish green 

 plants which look like scales. They grow on old fences, 

 rocks, trees, and the like and are especially noticeable 

 after a rain. A lichen is made up of the hyphse of a 

 fungus, which inclose the cells of an alga. The algal 

 cells in a flat lichen are usually near the top and bottom, 

 and the fungus is in the middle of the plant. The alga 

 uses the moisture which the fungus collects and brings to 

 the plant, and, by the use of its chlorophyll, makes food, a 



