2 Scientific Proceedings, Royal Dublin Society. 
present, but instead we find that the entire surface of the fibres 
is covered over with a web of fungal hyphe. We are here 
dealing with a “ mycorhiza”’; that is, the association of root fibres 
and fungal hyphe living in intimate physiological connexion with 
them. 
orcas 
Rhizome, with young aerial shoot (a) nat. size, showing numerous tufts of hairs (0). 
There may be advantages accruing both to the fungus and to 
the beech plant from such a union; the former may help the green 
flowering plant to obtain water and salts from the soil, while in 
return it may receive from its host some of the organic compounds 
manufactured in the green leaves. 
So essential to the well-being of the host plant is the presence 
of the mycorhiza, that if the development of the latter is prevented, 
the normal development of the beech plant does not take place ; 
and the relationship may perhaps be regarded as a true symbiosis. 
