CHAPTER IV 

 THALLOPHYTES 2. FUNGI 



DEPENDENT PLANTS 



33. The dependent habit. The Algae are said to be 

 independent plants because they can manufacture carbo- 

 hydrates from inorganic material. This means that they do 

 not depend upon any other plants or animals for their food 

 supply, and therefore could live and work if they were the 

 only organisms in existence. The Fungi, on the other hand, 

 are those Thallophytes that have no chlorophyll, and there- 

 fore cannot manufacture carbohydrates. This means that 

 they must depend upon other plants and upon animals for 

 their food supply, and that they could not exist in the ab- 

 sence of green plants. 



It must not be supposed that Fungi are the only dependent 

 plants, for even among seed-plants there are those without 

 chlorophyll, as Indian pipe and a number of orchids, that are 

 compelled to obtain their food from other organisms. But 

 the Fungi represent by far the greatest assemblage of de- 

 pendent plants. 



34. Parasites and saprophytes. If Fungi must obtain 

 their food from other organisms, it should be recognized that 

 there are two general conditions in which this food occurs. 

 It is either a part of the living body of a plant or animal, 

 or material that has been produced by a living body and is 

 no longer connected with it. For example, when the rust 

 fungus attacks wheat, it is obtaining food from living plants ; 



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