23 a BOTANY - OF THL LIVING PLANT 



in the root of Neottia. Here again the digestive process may result 

 in the transference of food materials from the fungus to the higher 

 plant There is no evidence that in the green Orchids the adult plant 

 is actually dependent on any such additional food : but the position 

 different with those Orchids classed as complete saprophytes, 

 of which Corallorhiza (Coral-root) and Neottia (Bird's Nest Orchid) 



Fig. 159. 



Section through the mycorrhizal region of the tuber of the Orchid, Phalaenopsis. 

 At the top of the figure are normal cells of the host ; at its lower limit are cells 

 crowded with fungal filaments, but still retaining their nuclei. Between these 

 zones are cells in which the fungal filaments have undergone digestion. An amor- 

 phous mass, or " clump," of undigested material remains, while the nuclei are 

 lobed. (After Bernard.) ( x 98.) 



are native examples. The former grows in Pine woods with its freely 

 branched rhizome embedded in rich humous soil. The rhizome 

 produces scale-leaves but no roots, while the aerial part of the plant 

 is a simple scape bearing only colourless scales and at the top a 

 raceme of small pale flowers. The tissues of the rhizome are freely 

 infected with mycorrhizal fungus. Neottia also grows in woods, and 

 if the plant is dug up the underground portion, which has some 

 imagined resemblance to a bird's nest, is found to consist of fleshy 

 roots crowded upon a short central rhizome which also bears scale 

 leaves. The plant throws up an aerial stem bearing only scale-leaves 

 and flowers, all being of a pale brown colour (Fig. 160). Rhizome 

 and root are freely infected with fungus. Both these plants, being 



