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group contains a vast number of kinds that, so far as form 

 and habit are concerned, are utterly diverse from eacii other. 

 It is not easy for instance to see any striking resemblance 

 between an ordinary mushroom or toadstool, and the rust 

 that grows on our grain, or the smut that disfigures our 

 corn. There is little outward resemblance between the 

 giant puff-ball, and the leaf spot of cotton or strawberry, 

 yet all these forms come under the same designation as 

 fungi. 



A second source of popular confusion has arisen from 

 the more or less one-sided way in which the subject has 

 been treated by popular or even scientific writers. Cer- 

 tain forms of fungi injurious to cultivated plants have been 

 writteu about, and naturally their ravages have been made 

 prominent. In this way the farmer has often been led to 

 believe that all fungi are enemies to be combatted with 

 Bordeaux mixture, and all sorts of spraying machines. A 

 comprehensive view of the group is rarely presented, 

 and it is desirable in this as in every other subject that we 

 form some definite notion of the subject in its general rela- 

 tions in order that our ideas may not be one-sided or 

 distorted. 



The group of plants known collectively as fungi — for 

 fungi are just as truly plants as any other form of vegeta- 

 tion — are associated together and distinguished from other 

 low forms of vegetation by a simple physiological charac- 

 ter, which can be easily recognized, notwithstanding the 

 fact that it is a negative one. This characteristic is the 

 inability to live on mineral or inorganic matter. Ordinary 

 green plants, high or low, have the power to take the 

 gaseous constituents of the atmosphere, together with 

 water and certain mineral salts found in the soil, and 

 through the agency of sunlight transform them into starch, 

 sugars, and other more highly organized forms of food 

 stuffs. This they are enabled to do by virtue of the pos- 

 session of a green substance, that which gives the color to 

 ordinary vegetation. This substance is called chlorophyll 



