SYMBIOSIS OF PHANEROGAMS AND FUNGI. 253 
membranous and transparent scales, and the extremity of each is bent back like 
a hook. The eylindrical flowers are developed at the top of the stem with their 
open ends turned to the ground, and are half-covered by the scales. Everything 
about this plant (stem, leaf-scales, and flowers) is of a pale waxen-yellow colour, 
and the general impression it produces is much more that of a Toothwort, or one of 
the colourless forest orchids, than of a species of primula or winter-green. Towards 
autumn, when ripe fruits have been produced from the flowers, the hitherto 
drooping extremity of the stem lifts itself into an upright position, whilst the 
entire aérial portion of the plant turns brown and dries up. Every disturbance 
caused by the wind, however slight, shakes out of the spherical fruits many 
thousands of tiny seeds as fine as dust, which, like the winter-green seeds, consist of 
only a few cells, and do not admit of the recognition of any differentiated embryo 
within them. Moreover, underground, the rhizomes, from which the small group of 
pale stems have arisen in summer, continue to live through the winter, and a 
number of new buds are developed on them. On digging down to the hibernating 
plant and removing the mould which conceals it, one finds at a depth of from 10 to 
40 centimeters bodies like coral-stems consisting of dense masses of roots crowded 
together and ramifying multifariously. All the root-branches are short, thick, 
fleshy, and brittle, and are matted together to form turf-like masses, which are not 
infrequently interwoven with the rootlets of pines, firs, and beeches, and have all 
their interstices filled with humus. Each rootlet is enveloped, right up to the 
growing apex, in a thick mycelial mantle. The hyphal filaments of this mycelium 
do not penetrate into the tissue of the root of Monotropa, nor do they send any 
haustoria into the superficial cells of these roots. The hyphz and the epidermal 
cells of the root are, however, in such close and continuous contact that sections 
exhibit a complete continuity of the tissues. 
Monotropa is therefore only able to withdraw nutriment from the hyphal weft 
of the mycelium so far as its subterranean parts are concerned, and, seeing that it 
is quite destitute of chlorophyll, and its aérial stem and leaves display no trace of 
stomata, the possibility of creating organic matter and of adding in general to its 
substance by means of its aérial parts is excluded. It therefore receives all the 
materials of which it is constructed from the mycelium of the fungus, whilst it is 
not in a position to render anything in return to this mycelium that it has not 
previously derived from the latter. If the mycelium subsequently withdraws any 
materials whatever from the still living or decaying Monotropa, the process is only 
one of restitution and not of exchange. Thus, in this case, there can be no talk of 
reciprocity in the processes of nutrition or division of labour such as occurs when 
there is symbiosis. The Monotropa grows in height and in circumference entirely 
at the expense of the mycelium in which it is imbedded, so that we have here the 
remarkable phenomenon of a Phanerogam parasitic in the mycelium of a Fungus. 
We so often come across the converse process in our experience that we cannot 
easily familiarize ourselves with the idea of a flowering-plant draining the 
mycelium of a fungus of nutriment: nevertheless there is scarcely any other inter- 
