140 FLOWERLESS PLANTS 



leaves and wood. But this is only half the 

 stoty. It has been proved that a very large 

 number of species of fungi — how many it is 

 difficult to say — are actually in the closest 

 association -with the roots of trees. The myce- 

 lium is not only entangled with the fibres, but 

 it often closely embraces, and even on occa- 

 sions penetrates, the young roots. There is 

 httle doubt that these fungi are helping them- 

 selves to the organic material which the tree 

 has been able to elaborate with its green leaves 

 in the sun and air above. So far there may 

 not seem to be anything very astonishing, but 

 there is a most singular side to the question. 

 Far from any harm arising to the trees, there 

 seems to be good proof that the presence of the 

 fungus on its roots is beneficial, and in some 

 cases essential, for the welfare of the host. 

 Although we must be careful not to dogmatise, 

 it really seems as if certain trees would not grow 

 at all unless the fungus guest was present. For 

 example, seedlings of beech and fir will not suc- 

 ceed in the chemical solutions ^^"hich suit other 

 plants so well. Further, it is a common ex- 

 perience for gardeners to find great difficulty in 

 estabhshing these trees, in common with rho- 



