7 



liable to attack, though a large number of trees are provided with 

 latex, resins, or gums, which close up a wound speedily and prevent 

 the Dlodgementof the fungus spores. Trees not thus protected are 

 very apt to suffer. Thus the Tembusu, when cut or badly pruned 

 is attacked by a black fungus which often damages it seriously. 

 The woody fungi Polyporns, Polystictus , Fomes, etc. are among 

 the most destructive parasites, and the appearance of the bracket- 

 like fructification on the trunk of a tree, almost certainly signi- 

 fies that the host is dying. Even more destructive than these are the 

 root parasites, Rosellinia etc. {See Bulletin No. 9, page 285) which 

 destroy all plants within a certain radius of the first infected tree. 



The timber destroying fungi of Europe have received some atten- 

 tion from the European Foresters, but at present little has been 

 done in those of the tropics. The destruction to forests by some 

 fungi in Europe and North America has been enormous, but less 

 damage is likely to be caused in our natural forests, as they are not 

 as in colder countries composed exclusively of one kind of tree so 

 that the infection is less likely to spread here, in the way that it 

 does in Europe. 



Fungi destructive to cut timber. 



The chief cause of the decay of timber is due to the attacks of 

 fungi, the growth of which is often very rapid. The spores ger- 

 minating under loose bark, or in cracks, or on the cut surfaces 

 develope the mycelium which penetrates the wood eventually 

 breaking it up. Some very hard timbers remain for many years 

 quite unaffected by fungus attacks, even in the most favourable 

 situations for their attacks, but most are sooner or later destroyed. 

 Where beams are so placed in buildings that they rest on one another 

 especially if in the dark, and where there is no current of air, they 

 are very liable to attack, and their destruction is very rapid, and it 

 is very common to find beams perfectly rotten at the ends where 

 they rest on each other, though quite sound in the more exposed 

 centre. When the mycelium has developed to a certain extent and 

 the weather is suitable, the fructification of the fungus is produced, 

 and the appearance of this which is commonly taken to be the whole 

 of the fungus may be taken as evidence that the wood is much in- 

 jured and the beam if in a building no longer safe. 



Soaking the timber in a solution of copper sulphate before using 

 it will disinfect it of any spores which may be on it and for a long 

 time at least prevent the attacks of any fungi, and indeed of 

 insects also. 



Among the most destructive of the fungi, are the following: — 

 Polystictus sa7iguineus, a brilliant red leathery fungus, bracket 

 shaped, about 2 inches across and comparatively thin. It is 

 common everywhere. 

 P. Idacino gitvus, a thicker lilac-coloured species. 

 Schizophyllum commune, a very common small greyish white 



fan shaped plant. 

 Lentinus exilis, Berk, a cup-shaped brown funeus. 



