NOTES ON WINTER BOTANY. 11 
The herbaceous stems are attacked in these moist and 
sheltered places by such fungi as Heterosphaeria patella, 
Melanomma, etc. The stalk eventually rots and is easily broken 
at the base by wind or accidents of sorts. Having been felled, 
the hollow centre is a neat and cosy refuge for insects and 
animals, and the whole stalk is soon attacked by a variety of 
fungi. A favourite position for Sphaerias is the soft tissue out- 
side the mechanical cylinder, and by their agency the epidermis is 
soon broken away. 
As regards the breaking up of leaves, a vast number of 
fungi attack dead rotting leaves when lying on the soil, but a 
very large part of the work must be done by animals. A curious 
fungus is Typhula Grevillei, whose minute club-like fructifica- 
tions may be found between the leaves and not upright. In such 
a position the spores must be distributed by worms, insects, or 
other animals which probably devour the fungus or the leaf 
substance, and so distribute the spores. 
But the most interesting facts are those connected with the 
rotting of tree stumps and the decay of fallen branches and 
twigs. The first point that one notices is the indestructible 
character of the cork sheet in which the woody parts are 
enclosed. It is not at all unusual to find cylindrical tubes of 
almost unbroken cork with the whole of the wood inside re- 
duced to powder. This is the more remarkable, as the 
Discomycete fungi, for instance, show extraordinary powers of 
adapting themselves to the most inappropriate foods. Species 
exist which grow on charcoal, leather, modelling clay, plaster, 
and fir tree resin. Yet, though 133 species at least grow on 
wood, those occurring on “ bark ’’ are very few, and even of these 
most, like Lachnella calycina, really live on the phloem and 
cambium, and only burst through the cork from the inside. 
Perhaps more remarkable is the resistant power of the sawn 
surface of the stump. This may remain discoloured and more 
or less hard for years after the tree is felled. It is apparently 
saturated with resin, and has a very scanty and difficult flora in 
which blue Algae (Chroococcus, Glaeocapsa, etc.) are common. 
Underneath this surface the wood may be entirely honeycombed 
or crumbling, powdery, and almost destroyed. But if hypnums 
or other mosses, liverworts, or lichens cover such a surface, it 
is soon decayed. 
