CHAPTER XIV 



THALLOPHYTES (Continued) 



Myxomycetes and Bacteria (Thallophytes lacking food-making 

 pigments) 



There arc three groups of Thallophytes — the Myxomijcetes, 

 Bacteria, and Fungi — which are characterized by the lack of 

 food-inaking pigments. Having no chlorophyll or other food- 

 making pigments, they are unable to carry on photosynthesis and 

 consequently must depend upon other organisms for their food. 

 Many obtain their food from the decaying bodies of other or- 

 ganisms, while others attack living organisms. 



As to how these plants arose, we are not certain. Although 

 some are the simplest of plants, they must have been preceded by 

 green plants, for otherwise there would have been no food for 

 them. They are no doubt degenerate forms of green plants, 

 having lost their food-making pigments as a result of their acquir- 

 ing the habit of taking food from other organisms. As will be 

 seen later in the study of these groups, the Bacteria have some of 

 the features of the Blue-green Algae, while the Fungi present a 

 number of features found in the Green or the higher groups of 

 Algae. But for the Myxomycetes we have no definite suggestions 

 of any relationships with other groups of plants. 



Being dependent plants, these Thallophytes are supposed to 

 have evoluted backward, rather than forward. The Fungi, the 

 most complex of the group, present nothing new over the Algae 

 in the way of evolution. To the evolutionists these groups offer 

 very little that is of interest. They concern us chiefly because 

 of their economic importance, 



Myxomycetes (Slime Molds) 



The plant body of the Myxomycetes, commonly called Slime 

 Molds, consists of a large slimy mass of protoplasm not enclosed 

 by cell walls, and hence the term myxomycetes from myxos 



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