FUNGOID PESTS OF FOREST TREES. 371 



Apple, as well as Larch. It commences as a round fleshy knob, but soon 

 expands into an irregularly flattened body, with a crisped and waved 

 margin, and often with several overlapping pilei, one above another. It is 

 not unusual to find well-grown specimens of a foot in expanse, and 

 wholly of a bright sulphur colour, the upper surface quite smooth, paler 

 as it grows old. The flesh is nearly white, soft, and easily broken ; the 

 under surface bright sulphur colour, and punctured with innumerable short 

 pores ; the whole fungus with a faint and rather disagreeable smell. 



This is an annual, which grows rapidly and decays in the autumn. 

 The spores obtain access through a wound, broken branch, or unprotected 

 pruning. The spores soon produce a mycelium which attacks the heart- 

 wood, which changes to a clear reddish-brown colour. 



Conidia are also produced in abundance from the mycelium in cavities 

 of the wood. 



It is important, therefore, to protect the ends of broken branches, or 

 parts exposed by pruning, by use of some fungicide. Also, to prevent 

 dispersion of the spores, all specimens found should at once be destroyed. 



Sacc. Syll. vi. 5050 ; Mass. Fun. Fl. i. p. 240 ; Mass. PI. Dis. p. 193, 

 fig. 45 ; Cooke, Hdbk. No. 752 ; Grev. Sc. Crypt. Fl. pi. 113 ; Soiv. Fungi, 

 t. 135 ; Hart. & Som. Dis. Trees, 200 ; Marshall Ward, Timbers, &c. 

 p. 165, fig. 17-19. 



Wound Parasites. 



Other of the large Hymenomycetal Fungi have the reputation of being 

 destructive to forest and orchard trees as wound parasites, but we are 

 inclined to think that the injury they cause is proportionately small, as 

 only individual trees are affected, and only those which have suffered 

 previous injury. 



Tinder Fungus. 

 Fomes fomentarius (Fries). 



This woody fungus is said to be a wound parasite of Beech and Elm 

 as well as old fruit trees. The pileus is shaped somewhat like a horse's 

 hoof, from three to seven inches across, dingy brown, marked with con- 

 centric ridges, smooth, and at first whitish at the edge. The under surface 

 is almost flat, whitish, then brown, densely perforated. The substance is 

 rust-coloured and fibrous, and rather spongy, but dry, and may be beaten 

 out into the substance known as amadou or German tinder. The spores 

 are oval and brown. 



Sacc. Syll. vi. 5409 ; Mass. PI. Dis. 185, 392 ; Cooke, Hdbk. No. 776 ; 

 Sow. B. F. t. 133 : Journ. B.H.S. xxvi. 1902, p. 734, fig. 308 ; Mass. Fun. 

 Fl. p. 220. 



False Tinder Fungus. 



Fomes igniarius (Fries). 



This also is reputed to be a wound fungus of the Oak, as w T ell as some 

 other trees. It resembles Fomes fomentarius externally and superficially, 

 but is minutely velvety when young, becoming blackish and cracking. 

 The under surface is cinnamon-coloured, and the flesh is very hard, rusty- 



