252 SYMBIOSIS OF PHANEROGAMS AND FUNGI. 
Special importance is given to the social life by the fact that the chief species of 
Phanerogams participating in it are of gregarious growth and cover whole tracts of 
country, forming boundless heaths and measureless forests, as, for instance, the 
various heaths, the oak, the beech, the fir, and the poplar. The conception of this 
subterranean life affecting every moorland and vast timbered tract is one full of 
wonder and interest. 
We can now see why it is that the ground in woods is the abode of such a 
profusion of fungi. No doubt some of these fungi draw their nutriment exclusively 
from the store of dead plant-organs accumulated there; but others, as certainly, are 
in social connection with the living roots of green-leaved plants. It is true we 
cannot yet state precisely what are the species of fungi which contract this sort of 
union, or whether generally a definite elective affinity exists between certain fungi 
and certain green-leaved plants. There is much in favour of this supposition in 
a few cases: but, on the other hand, it is very unlikely that each of the various 
Phanerogams occupying a limited area of ground in a pine-forest, where a few 
square meters of earth contain so many tangled roots belonging to pines, spurge 
laurels, bilberries, cranberries, heath, and winter-green, that they can only be 
separated with difficulty, should select from the great host of fungi growing in the 
forest a different partner. In instances of this kind it seems just to suppose that 
the mycelium of one and the same species of fungus enters simultaneously into 
connection with all or several of the plants growing close together; it is similarly 
probable that the mycelia of different species of fungi render to one and the same 
flowering-plant the service of absorption according to the locality in which it occurs. 
This surmise is supported by the fact that when certain species, brought from distant 
parts and regularly exhibiting mycelial mantles on the ends of their roots, are 
reared in our gardens and greenhouses from seed, they unite in these abodes with 
fungus-mycelia, which certainly do not exist in the regions where the Phanerogams 
in question grow wild. Thus, for instance, the roots of the Japanese tree, Sophora 
Japonica, and those of the Epacridez of Australia, are found in European gardens 
in social union with fungi, which with us are native, but which certainly do not 
oceur in Japan or Australia; and it is therefore scarcely open to doubt that the 
Sophora Japonica, to take one example, associates itself with different fungi in 
different regions. 
Now that the symbiosis of fungi devoid of chlorophyll with green-leaved 
Phanerogams has been discussed, we are for the first time in a position to deal with 
that most remarkable of all cases of food-absorption wherein the subterranean roots 
of a flowering-plant are completely wrapped in a mycelial mantle, whilst the parts 
which shoot up above ground bear no green leaves, and, in general, possess no trace 
of chlorophyll. Such is the case of Monotropa, the various species of which are 
intimately allied in the structure of flowers and fruit with the Primrose and Winter- 
green, and are met with scattered everywhere in shady woods. Their stems, which 
are from 10 to 20 centimeters in height and emerge from the mould of the forest- 
ground in summer time, are thick, fleshy, succulent, and profusely beset with 
