CONTENTS 



CHAP. PAGE 



I. INTRODUCTION. 



The relation of a fiuigus 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 cankw 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 woimds as a 

 source of canker. Contributory causes of canker. Methods of 

 prevention. The synonymy of Dasyscypha calycina , . 52 



V. HEART-ROT. Fomes annosus. 



Various fimgi which cause heart-rot. Fomes annosiis : 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 ; conidiophoies. 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, Porta vaporaria, Polyporus sulphu- 

 reus, Trametes Pirn . . . ... . . .126 



