162 PLANT LIFE 



fruit. We often speak of them as degraded 

 or degenerate forms, but this is a somewhat 

 loose and inaccurate form of expression. The 

 vegetative structure has, it is true, been 

 simplified, but in such a way as to render 

 the plants much better adapted to the new 

 conditions of nutrition than they ever could 

 have been had they retained the complexity 

 appropriate to the green ancestral type. 



For the moment we will pass over the 

 bacteria, which differ in many respects from 

 other plants, and survey the most salient 

 features presented by the fungi. 



Fungi, like the flowering parasites above 

 mentioned, have descended from green 

 ancestors, but it is among the lower ranks 

 of the vegetable kingdom that their origin is 

 to be sought. It is tolerably certain that the 

 class of fungi, as we know them to-day, repre- 

 sent a number of not very closely related 

 families, and that these have descended from 

 more than one chlorophyllous algal stock. 

 There is no reason, therefore, to think that 

 their vegetative structure has undergone 

 very important alteration in the direction of 

 simplicity. It would probably be more in 

 accordance with facts to say that it has never 

 emerged from a primitively simple type of 

 organisation. 



The body of a young, actively growing 

 fungus consists entirely of simple tubular 

 threads, or hyphce, which, in the majority of 

 species, are partitioned by cross walls. These 



