PARASITIC rUKGI 



O 



miislirooms, which may be sent up into the air above the 

 soil surface in a single night. Each mushroom (Fig. 1) 

 consists of a stem commonly surmounted by an umbrella- 

 like cap, on the under side of wliich are many thin ver- 

 tical jilates. Between thece plates vast numbers of 

 spores are soon produced, to fall to the ground, or to be 

 wafted hither and thither by the winds. As soon as the 

 spores are ripe the fungus dies. It will be noted that 

 this plant has no chlorophyll, 

 and is simply nourished by 

 dead and decaying organic 

 matter. Fungi like this are 

 said to be sapropliytes, or 

 saiJropliytic, a w^ord meaning 

 living on decaying materials. 

 Such plants, as a rule, do no 

 direct injury to other kinds 

 of vegetable life. 



There are many kind;^ of 

 fungi which, instead of living 

 upon dead or decaying organic 

 matter, develop at the expense 

 of other living organisms. 

 Consequently these are said 

 to be parasitic in their nature. 

 Some of these live within the 

 bodies of animals, often kill- fig. 2. chinch bugs affected 

 ing their hosts, and others ^'^ fungus. 



live within the tissues of the higher plants. A good 

 example of the former is seen in the fungus which de- 

 stroys chinch bugs, represented in Fig. 2. A number 

 of dead bugs are shown on a wheat stalk on the left, 

 while a single bug, much magnified, covered with the 

 fungus, is represented at the right. This fungus belongs 

 to a genus of plants called by botanists Entomophthora. 



To illustrate the manner of development of the par- 

 asitic fungi affecting higher plants, we may take the 



