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and each one that reaches a suitable place for sprouting is 

 able to smut a head of grain the following year. Still 

 other spores can be seen in the rusty or black lines that ap- 

 pear on the stems of various small grains. These lines are 

 simply the masses of spores of the parasitic fungus break- 

 ing through the surface of their host plant in order to spread 

 the rust to other plants or to hold the fungus over the 

 winter to attack the young grain of the following season. 



A spore then is a reproductive body that has the same 

 office as a seed, but differs from it in its microscopic size 

 and simple structure. When the spore germinates it pushes 

 out a minute germ tube which becomes what we call a hypha. 

 The spores of fungi have a definite form when viewed through 

 a microscope. Some have characteristic shapes so that the 

 particular group to which they belong can be easily recog- 

 nized. In others the shape is less characteristic, but the 

 form of spore produced by any one species is as constant 

 for that species as the shape of the seed produced by any of 

 the higher plants. 



Definition of a Fungus. 



A Fungus then is (1) A plant that has as definite a life 

 history and mode of growth as a cotton plant, an oak or any 

 other form of vegetation. (2) Is devoid of chlorophyll or 

 the ordinary green color of vegetation. (3) Possesses a 

 simple structure, and (4) Keproduces itself by means of 

 spores. 



In structure, fungi vary as widely as do the higher forms 

 of vegetation. Some of the simplest, like the yeast-plant, 

 consist of a minute drop of semi-lluid siibstance (protoplasm) 

 surrounded by a delicate covering known as the cell wall, the 

 whole not over one three-thousandth of an inch in diameter. 

 More complex forms like the moulds, form delicate thread- 

 like structures {hyph(v) which frequently interlace into a 

 tangled, matted or more or less felty mass {mycelium). Some 

 of the larger forms are gelatinous, some are fleshy, some 

 leathery, corky or even firm and woody, but in each case 

 this structure is developed by some modification of the 



