242 CRYPTOGAMS 



them with a liberal supply of spores, close them, and place 

 one in a very cold place, the second in a warm place, and 

 the third where it is quite hot. After one week, bring the 

 preparations together and compare results. Inference? 



3. Light. Prepare two Petri dish cultures as before, placing 

 one in a dark or semidark place, and the other on a window 

 sill where it will receive direct sunlight. After one week 

 bring them together and compare. Inference? 



4. Air Supply. Make two Petri dish cultures, placing one 

 under cover and the other where the air can freely blow over 

 it. After a week, bring them together and compare them. 

 Set a culture on which a fine growth of mold is growing 

 where the wind can blow over it. What result? What 

 may be inferred from this experiment? 



Note. The canning of fruit depends largely on exclusion of 

 molds. The heating of the fruit is designed to kill molds which 

 may have found access to the fruit. The cans are closed quickly 

 while the contents are still hot so that no spores can get in. The 

 sealing must be air-tight to prevent molds from getting in before 

 the fruit is eaten. In spite of all these precautions, sometimes 

 molds will find entrance and spoil the fruit. 



208. FUNGI 

 Object. To sturdy a mushroom. 



Mushrooms may be found in rich woods, fields, meadows 

 wherever there is abundant decaying vegetable matter. 



These plants are saprophytes, that is, living on decaying 

 substances. They are important economic plants for the 

 reason that they aid in the removal of dead vegetation. 



Method. Draw the fungus after having studied it to 

 make out the following parts: the cap (umbrella or pileus), 

 the column (stipe or stalk), the gills or flat plates which extend 



