THE LARCH CANKER 75 



rise to most of the serious cankers on main t-runlvs. Tiie 

 third is less important, since it only affects trees which are 

 being killed out through lack of light. The importance of 

 womids has been over-estimated by most j^revious writers. 



Contributory causes, rendering the tree more liable to 

 canker, are any agencies which cause wounds, damp stagnant 

 atmosphere, and poor badly-drained soil. Pure larch 

 plantations are more liable to the disease than those where 

 the trees are intermixed with hardwoods. In general it 

 may be said that any conditions which are prejudicial to 

 the vigorous growth of larch are favourable to the spread 

 of the disease. 



Healthy plantations can best be grown by selecting sites 

 where all the conditions are favourable to larch growth, 

 but a treatment has been suggested whereby it may become 

 f)0ssible to grow sound trees where canker has usually been 

 epidemic. By the pruning of branches it is hoped that 

 infection from these members may be prevented. 



Ok the Synonymy of Dasyscyplm calycina, (iSchum.) 



Fuck. 



The literature of larch canker has become much confused 

 by the variety of names which have been apphed to the 

 fungus causing it. 



Berkeley (1859) called it Peziza calycina ; Willkomm 

 (1867) confused it "with a somewhat .similar member of the 

 Basidiomycetes, Corticium amorpJmm, and called it by that 

 name ; Hoffmann (1868) corrected this error, and adopted 

 the same name as Berkeley ; and Hartig (1880) said that 

 the fungus showed microdimensional differences from 

 P. calycina, and instituted a new name, Peziza Willkvmmii. 

 Most English mycologists, however, have refused to adopt 

 this new name, maintaining that the conventions of nomen- 

 clature demand that it should be called Dasyscypha calycina. 



This confusion has arisen from the fact that there are 

 three or foii^ different species of Dasyscyjjha which are 

 indistinguishable with the naked eye or a pocket lens, and 



