CHAPTER II 



THE RELATIONS OF FUNGI TO OTHER PLANTS 



The whole array of plants known to science, of which there are 

 some two hundred thousand different species, may be conveni- 

 ently grouped in three great divisions, each of which can be fairly 

 well characterized by certain more or less easily recognized marks. 

 The comm.on herbs, shrubs and trees that constitute vegetation in 

 the ordinary sense, each produce some structure recognizable as 

 a flower and develop seeds in their process of generation. Such 

 plants form a convenient and easily-recognized group known as 

 seed-producing plants or spcrmaphytes. 



The second great division is not characterized by common 

 structures so well known as seeds, but may be recognized as con- 

 taining plants which do not develop seeds but still possess a leafy 

 axis. The higher forms with woody tissues are well known as the 

 ferns and their allies, and the lower and simpler forms are known as 

 mosses. From the common form of the ^%^ apparatus found in all 

 these plants they have been called collectively archegoniates. Pass- 

 ing still lower down the scale of plant existence we find a series of 

 plants of still simpler structures which do not develop a leafy axis, 

 but which are formed of masses of cellular tissue ranging in vari- 

 ous species from a flat leaf-like expansion of cells, through thread- 

 like forms, to series of single microscopic cells entirely separate 

 from each other. Such an irregular expansion of vegetation we call 

 athallus, and it has become convenient to speak of all such plants 

 as thallopJiytes. Here the green slimes, the pond-scums, the sea 

 lettuce, the rock-weeds, the red algae and all the hosts of fungi 

 from yeast to mushrooms are included, altho the plants thus 

 associated form a most unwieldly and heterogeneous assemblage 

 of organisms. 



Summarized and arranged in reverse order so as to group the 

 simpler forms first, we have the following tabular survey of the 

 vegetable kingdom : 



8 



