THE PERENNIAL PSEUDORHIZA 379 



was six inches in diameter. There was nothing to be seen at the 

 time above-ground to indicate that the tree was in a moribund 

 condition ; yet moribund it actually was. In August, 1914, I 

 revisited the tree and found that the clusters of Collybia fusipes 

 fruit-bodies on the ground round about the trunk were even more 

 numerous than in 1912, for there were fifteen clusters instead of 

 nine. Ten of these clusters were within 3 feet of the trunk, two 

 about 5 feet distant from the trunk, and one 9 feet distant. The 

 distances of the other two groups from the trunk, owing to an over- 

 sight, were not recorded in my notes. The tree was now evidently 

 suffering from disease, for the bark on one side of the trunk appeared 

 to be going rotten and adventitious roots which had grown out 

 here and there in its cracks were already dead. There were leaves 

 on all the chief branches, but they seemed to be fewer than on 

 neighbouring trees of the same size. About two years later (1916 ?), 

 during my absence from England, the tree, on account of its dying 

 condition, was cut down and removed. As we shall see, the gradual 

 death of this tree was accompanied by an extensive destruction of 

 its roots by the mycelium of Collybia fusipes, and the clusters of 

 fruit-bodies which appeared above the roots year after year were 

 nothing but the visible 'subaerial signs of the destruction of the 

 tree's subterranean root-wood. 



When, in 1912, I beheld nine clusters of Collybia fusipes fruit- 

 bodies scattered in the leaf -mould under the Beech tree as just 

 described, it at once occurred to me that the fungus might be a 

 root-parasite. I therefore carefully excavated the leaf-mould and 

 soil covering the bases of several of the clusters. As a result I 

 found that every fruit-body cluster was attached to a root. The 

 mycelium of Collybia fusipes growing in the forest floor, therefore, 

 is to be sought for not in the leaf-mould but in the wood of buried 

 roots. 



One of the Collybia fusipes clusters which, at a distance of 12 feet 

 from the Beech trunk, was attached to a stout Beech root, is shown 

 one- third its natural size in the photograph reproduced in Fig. 189. 

 The cluster was made up of five large fruit-bodies, the smallest of 

 which had a pileus two inches in diameter and the largest a pileus 

 six inches in diameter. The five fruit-bodies were all connected 



