CONTENTS 



CHAP. PAGE 



I. INTRODUCTION. 



The relation of a fungus to its host. Life-history of a fungus. 

 The morphology of the larch ; long and dwarf shoots ; internal 

 structure of the stem ........ 1 



II. THE LARCH CANKER. 



General. Historical. The mycelium of Dasyscypha calycina 

 and its effect on the tissues. The canker as a pathological 

 structure .......... 16 



III. THE LARCH CANKER (continued}. 



The reproductive organs of the fungus. Germination of spores. 

 Pure cultures on nutrient media. Artificial infection with canker 37 



IV. THE LARCH CANKER (concluded}. 



On the mode of infection in nature. Importance of wounds as a 

 source of canker. Contributory causes of canker. Methods of 

 prevention. The synonymy of Dasyscypha calycina . . 52 



V. HEART-ROT. Fomes annosus. 



Various fungi which cause heart-rot. Fomes annosus : general ; 

 historical. Secretions induced by Fomes annosus : turpentine 

 and resin ; soluble gum ; insoluble gum. Decomposition of the 

 wood 80 



VI. HEART-ROT. Fomes annosus (concluded}. 

 Reproductive organs : fructifications ; conidiophores. Pure 

 cultures on artificial media. Cultures on natural media. Infec- 

 tion experiments. Mode of attack in nature. The frequency 

 of heart-rot in plantations which form the first rotation on culti- 

 vated soil. Methods of prevention . . . . .100 



VII. HEART-ROT CAUSED BY OTHER FUNGI. 



Polyporus Schweinitzii, Poria vaporaria, Polyporus sulphu- 

 reus, Trametes Pini 126 



