492 FOMES APPLANATUS (PERS.) WALLR. IN SOUTH AFRICA. 



also drawn to forms of the same fungus, which occur in South 

 Africa. 



Methods of control should follow preventative lines, which 

 are best attained by proper forest sanitation, such as the destruc- 

 tion of sporophores of the fungus and of diseased wood. 



Acknowledgments. 



My thanks are due to Mr. I. B. Pole Evans, Chief of the 

 Division of Botany, for placing certain references at my dis- 

 posal, and also for allowing- me to examine some material in 

 his herbarium. 



I also acknowledge the assistance given by various officers 

 of the Forestry Department, and especially Mr. J. D. Keet in 

 collecting specimens of this as well as other Polyporaceae, as also 

 for notes which frec|uently accompanied the specimens. 



Some specimens of this fungus were verified by Mr. C. G. 

 Lloyd, of Ohio, and him I thank for assistance with the Polypo- 

 raceae generally. 



The drawings were kindly made for me by Miss K. A. 

 Lansdell, of this Department (Natal Herbarium, Durban). 



Explanation of Illustrations. 



Pig. I. — Highly magnified transverse section through black 

 ironwood to show the delignification and digestion of the 

 wood brought about by this fungus. The dotted regions 

 gave reactions for cellulose with chlorozinc iodide, and the 

 digestion is evident from the cellulose plates projecting 

 into the lumina. 



Fig. 2. — Section highly magnified, and showing the mycelium 

 of the fungus in the wood of black ironwood, and passing 

 from cell to cell through the pits in the cell walls. 



Plate 14. — Photographs of sporophores of Fomcs applanatus 

 from stumps of Acacia mollisinia. The specimens are in 

 the herbarium of the Government Mycologist at Pretoria, 

 and the numbers are those of that herbarium. 



Plate 15 a. — Photograph of wood of diseased black ironwood. 

 which has already been considerably delignified, and crum- 

 bled easily hetween the fingers. 



Plate 15 b. — Sporophore of Pomes applanatus from dead Podo- 

 carpus sp. 



Plate 15 c — Abnormal laterally stalked form oif Pomes appla- 

 natus from Olea laurifolia (black ironwood). 



Plate 16. — Spores of Pomes applanatus. Highly magnified. 



Plate 17 a. — Nodules of Pomes applanatus, which develop into 

 the bracket-shaped sporophore. 



Plate 1/ b. — Poly poms gibbosus Nees. No. 1703 from Her- 

 barium of Government Mycolog'ist, Pretoria. This fungus 

 is most probably only a form of Pomes applanatus. 



Plate 17 c. — Abnormal laterally stalked form of Pomes appla- 

 natus from dead Rhus Iccvigata (red currant). 



(Read, .fuly 3. 191 7.) 



