FUNGI AND .LICHENS. 113 



Another less brightly-coloured species is often found 

 in company with it, but in this the under-surface has 

 a tinge of purple. 1 



Turning from the dead stumps for a moment to 

 the fallen branches of an oak, lying on the 

 ground in a state of decay, we shall find that 

 although but recently shaken down by the wind the 

 branch has rotted upon the tree, and may be broken 

 into fragments with the slightest effort. If the 

 weather be moist we shall be -sure to find on these 

 fallen branches little black masses of a shaky, 

 tremulous substance about an inch in diameter, with 

 the under surface rough like black crape ; but if the 

 weather be dry these will have shrivelled into shining 

 flat patches like blotches of pitch. Placed in water 

 for half-an-hour these shrivelled specimens swell, and 

 again assume the same dimensions and appearance 

 as when in their fresh and growing condition. This 

 is the " Witches' Butter," 2 one of the Tremelloid 

 Fungi ; of which several species will be found on 

 dead branches, some in convolute masses as large as 

 the fist, some not unlike mulberry fruit, and some 

 as small as the head of a good-sized pin. They all 

 contain a large amount of water in their composition, 

 so that they shake and tremble like masses of jelly 

 when moist and fresh ; but as they become dry the 

 water evaporates, and the fungus shrinks and shrivels 

 almost to a mere film. 



It is by no means uncommon to see dead branches 

 lying on the ground, and bearing upon them a 



1 Stereum purpureum. 2 Exidia glandidosia. 



