CO-OPERATION OF PLANTS. 211 



myceloid filaments of the fungus already existing in the soil ; 

 henceforward the connection continues until death. As the root 

 grows onward the myceloid fungus grows with it, accompanying it 

 like a shadow whatever its course. The ultimate ramifications of 

 roots of trees a hundred years old, and the young roots of year 

 old seedlings, are both covered by the myceloid mantle in the 

 same manner. Gardeners for years have experienced great diffi- 

 culty in rearing various specimens of rhododendron, winter green, 

 broom, heath. This difficulty is now traced to the fact that the 

 roots of the rhododendron, for example, is unable to find its sym- 

 biotic partner in some soils in which it is transplanted, or through 

 which the new roots are piercing their way ; the transplanted 

 rhododendron, therefore, perishes on account of its being unable 

 to assimilate the necessary materials from the soil. On the other 

 hand, the roots of the healthy, vigorous rhododendron are found 

 to be invested by the fungoid partner. 



The partnership or symbiosis, therefore, in the instance just 

 mentioned is between the rhododendron and the fungus which is 

 attached to its roots. The larger tree providing the fungus with 

 starch and other organic materials elaborated in the green leaves 

 of the tree, whilst the smaller plant supplies the rhododendron 

 with moisture and mineral matters which the fungus absorbed 

 from the ground. The filaments of the fungus grow in sinuous 

 curves, forming a felt-like coat round the root. In colour the 

 filaments are mostly brown or grey, and through the tangle of 

 fungus filaments the root may often be discerned here and there, 

 whilst in some instances the fungus even penetrates some distance 

 into its partner. The fungoid plant is provided externally with 

 hyphae, or hair-like processes, which pierce the earth, taking up 

 nutriment, and handing it over to its larger partner. 



A further proof that a symbiotic partner is indispensable to 

 certain plants, is found in the fact that when the attempt to rear 

 seedhngs of the beech and fir is made in a soil destitute of humus 

 (that is, fungus filaments), the seed, after germinating and growing 

 a short time, perishes ; but if soil or mould, recently dug from the 

 ground in a wood, and known to contain the living mycelium of 

 the fungus, be placed at the root of the seedling, it at once begins 

 to grow vigorously, owing to it having " connected on " with the 



