lo INTRODUCTION TO THE STUDY OF FUNGI 



heat, with a suitable matrix, the filaments of this mycelium 

 have been revivified, and by a profuse and rapid growth they 

 have spread over, and penetrated the whole of the soil of which 

 the mushroom bed is composed, and constitute the vegetative 

 system of the mushrooms which afterwards appear on the 

 surface. This mycelium represents an important element in 

 the morphology of all Fungi. It is rarely reduced to such 

 small proportions as not to be recognised, but, practically, it 

 is possibly never wholly absent. We may start, therefore, 

 with what we may regard as an essential attribute of Fungi, 

 and the representative of the purely vegetative system. Where- 

 ever we see a Fungus of the mushroom type, whether we please 

 to call it a mushroom or a toadstool, we may find the mycelium 

 in the soil from which it springs. In the autumn, if we stir 

 up and turn over any clump of dead leaves or other decaying 

 vegetable matter in a damp situation, we shall be sure to find 

 a profusion of this mycelium, even though no perfect Fungus 

 makes its appearance, and it is at work on every dead stump 

 and every fragment of rotten wood. 



Mycelium consists of hyphae or threads, usually septate, 

 sometimes simple, but mostly branched, increasing by growth 

 at the extremities, and gregarious, so as to form reticulated 

 interwoven masses, either in a thin network or a densely-felted 

 mass. In a certain sense they are analogous to the roots of 

 flowering plants, and, like them, draw moisture and inorganic 

 constituents from the soil or other matrix on which they may 

 be developed. It is another axiom with Fungi that, by means 

 of the mycelium, they derive their sustenance from the matrix 

 on which they grow. It cannot be doubted that the growing 

 points of the mycelium possess the power of penetration by 

 the production of a ferment, since they are capable of pene- 

 trating the hardest wood, disintegrating the cells, and reducing 

 it to powder. The ordinary mycelium found amongst dead 

 leaves has a power of disintegration, and soon reduces them, 

 as well as twigs and stems, to a condition of humus ; but the 

 progress of mycelium in a dead trunk is quite as definite and 

 certain. Who can doubt the disintegrating power of the 

 mycelium of the " dry rot," and it must be borne in mind 

 that it is the mycelium in this instance which works the 



