228 NATURE STUDY AND AGRICULTURE 



of the leaf. Notice the clusters of small black bodies. 

 What do you think these are? In these spore cases are 

 small spores for the reproduction of the plant. This 

 fungus is known as lilac mildew. Since it lives upon a 

 living plant it is called a parasite. The plant upon which 

 it lives is called its host. Can you think of any other 

 parasitic fungi? If possible have in class some ears of 

 corn covered with smut. Examine this. What is it com- 

 posed of? The mass of black sooty material is chiefly 

 made of spores. What is the effect of this fungus on the 

 ear of corn ? The smut plants have really penetrated the 

 young grains of corn, and have lived upon these grains. 

 Has this fungus many or few spores? Much corn is 

 destroyed by this disease. What other grains are attacked 

 by smut? Both wheat and oats. 



Save at harvest time a few heads of oats or wheat with 

 smut on them. Can you find any spores in these ? What 

 will every spore produce ? A new plant, which, like all the 

 other fungi studied, forms a mycelium. It usually begins 

 its growth when the oat plants are about an inch high. 

 The threads (hyphae) of the fungus feed upon the growing 

 oats, sometimes so weakening the plant that it dies. Do 

 you think any of the oat seeds are likely to have spores on 

 them if they have grown in a field where some of the heads 

 had been affected with smut? Can you think of anything 

 that might be done to kill these smut spores ? 



Formaldehyde will kill these spores just as readily as it 

 did the mold spores. The following recipe is used by 

 many farmers: Put one pint of forty per cent, formalde- 

 hyde in thirty-six gallons of water, soak the seeds in this for 

 ten or fifteen minutes, and then spread out to dry. This 



