MICROSCOPE AND AGRICULTURE 



become filled. The smuts are very important but 

 are not of much interest as objects for the micro- 

 scope, so we will pass them over for subjects of 

 greater interest if of less importance. 



Every farmer knows the familiar and destructive 

 fungus known as " rust of wheat," it is one of a 

 large class of most interesting plants. The " rusts " 

 are interesting to the microscopist on account of 

 their structure and to the botanist because they 

 cannot, like other fungi, complete their lives upon 

 one plant. They derive their popular name from the 

 fact that they look like patches of rust upon the 

 plants on which they live. Some of the greatest 

 living agricultural botanists have spent many years 

 on producing races of wheat upon which rust fungus 

 will not grow. Wonderful success has rewarded 

 their efforts and conferred immense benefits upon 

 farmers. In spite of this, however, we need not 

 despair that we shall be unable to find a specimen 

 for our microscope, though it is happily an un- 

 doubted fact that the disease is not so common now 

 as a few years ago. 



Rust of wheat fungus grows part of its time on 

 barberry leaves and part on wheat. In the summer, 

 if we examine one of the rust-like patches on stem 

 or leaf of wheat we shall see that it consists of a 

 dense bunch of small, short stalks each one of which 

 is terminated by an oblong red-brown spore. If we 

 keep another patch of the fungus under observa- 

 tion, we shall find as the season advances, that 

 instead of the red-brown patch it has grown darker 



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