452 The Living Plant 



but they show, for the most part, a double structure imposed by 

 their habit of life. First, they possess a feeding body, called a 

 mycelium, consisting as a rule of innumerable fine, slender, white 

 threads ramifying and radiating everywhere throughout the 

 accessible tissues of the living plants, or amongst the decaying 

 materials upon which they live; and second, they possess a com- 

 pact spore-forming body which comes to the surface, and thus 

 carries the spores to a position where they can be scattered by the 

 wind. Most of the Fungi familiar to us, such as Rusts, Bracket- 

 fungi, or Mushrooms, are simply the spore-forming bodies of 

 feeding mycelia which branch profusely, though invisibly, through 

 green tissues, tree-trunks, or earth. And it is an interesting 

 speculation, by the way, whether kinds like the Bacteria, whose 

 structure and habit do not permit them to bring their spores 

 thus to the surface for dissemination, may not cause the death 

 of their hosts as an adaptive measure in order that their spores 

 may be set free by the decomposition of their victims. The 

 cellular anatomy of the Fungi differs in a curious particular 

 from that of the Algae and other kinds of plants, for the habit of 

 forming the thread-like feeding mycelium persists in the spore- 

 forming body, which is simply a collection of compacted and 

 parallel cellular threads; and this explains why it is that Mush- 

 rooms, for instance, break apart in the fibrous-grained way that 

 they do. In size the Fungi are all rather small, ranging from 

 minute-microscopic up to the Toadstools and the Bracket-fungi, 

 which never exceed some two feet across, though to the size of the 

 spore-forming bodies must be added that of the radiating myce- 

 lium, which may range, albeit tenuously, over a diameter of several 

 feet. In color the Fungi are not green, at least of the chlorophyll 

 shade, for their most distinctive feature is the total lack of that 

 substance; but they are typically white, verging to gray shades or 

 brown. The spore-forming bodies, however, are brilliantly 

 colored in yellows, purples, and reds in some kinds, notably the 

 Rusts and the Smuts, and especially some of the poisonous Toad- 



