LIST OF ILLUSTRATIONS 
FIG. 
1. Section through canker : : 4 A Frontispiece 
2. Transverse section of one-year-old stem of larch . - page 8 
3. 38 55 » three-year-old stem oflarch . facing page 8 
4, 5 35 » abnormal wood : 2 op tk Ss 8 
5. Method of formation of periderm . : . - page 10 
6. Longitudinal section of phloem ; ae Il 
7. Transverse section of phloem ‘ : , ‘ e § 13 
8. Canker healed on both sides . : : . facing page 18 
9. Canker which has nearly girdled stem ; ba * 18 
10. Mycelium of Dasyscypha in wood of larch . page 27 
1l. Radial longitudinal section of abnormal wood . 35 32 
12. Stages in the development of a canker 35 34 
13. Canker on young larch showing swelling at back . facing page 36 
14. Canker showing swelling at sides - is <4 36 
15. Apothecia of Dasyscypha calycina on dead me stem. 
Dry weather. . 33 » 37 
16. Apothecia of Dasyscypha anaes on dead larch stem. 
Wet weather . F o> 35 5 37 
17. Section through actinic of ee ae calycina . - page 38 
18. Dasyscypha calycina, reproductive organs 40 
19. Ascus which has discharged its spores: : ae kes 41 
20. Spores and germination . ‘ Sys 43 
21. Growth of mycelium in drop cultures 5 : a 45 
22. Pure culture of Dasyscypha calycina on nutrient 
gelatine . r : . : ; a . facing page 48 
23, Pure culture on sterilized larch stems showing 
apothecium P 5 i ‘ os obs 2, 48 
24. Canker showing origin foi branch a 35 35 56 
25. 53 ” *” 3 Subsequently 
healed on oneside . . : : ‘ ae » 56 
26. Cork layer across base of branch 3 ‘ . - page 60 
27. Canker fungus spreading down froma branch . . facing page 61 
28. Spread of fungus down the branches ‘ i Soar » 61 
