PLANTS WHICH CAUSE DECAY 



397 



on which they grow ? Can foods be protected against 

 them in the same way as against bacteria ? l 



An immense amount of damage, amounting in the 

 United States alone to a great many 

 millions of dollars each year, is done 

 to crops by the Smuts, Eusts and NMSW^ 5 



Mildews. For this and other reasons 

 it is worth while to devote some 

 study to these plants, in order that 

 we may more clearly understand their 

 mode of life and the best remedies 

 against them. 



The common Corn-smut begins to 

 appear in the leaves when the plant 

 is three or four feet high, forming 



'" ' 221. Green Mould of cheese, 



small white spots raised above the etc -. **"*$***** mun - 



ner in which the spores 



surface of the leaf and somewhat 

 wrinkled (frequently surrounded by a reddish dis- 

 coloration of the leaf). Later on they turn black 

 (or disappear altogether) . The Smut appears on 

 the stalk, inside the sheathing base of the leaf, near 

 the joint or node. It also appears in the form of 

 pustules scattered through the male flowers or tas- 

 sel ; it also appears on the ears, covering them 

 partially or completely, forming white masses with a 

 peculiar soft, silvery luster ; later these burst and 



1 A very good method of sealing jellies is to pour melted paraffin on top : 

 the heat kills the Moulds and bacteria while the paraffin seals the tumbler her- 

 metically,, 



