XIII.] "DAMPING OFF" OF SEEDLING-TREES. 285 



itself when the conditions are most favourable for its 

 development and well-being 



It has already been mentioned that other plants 

 besides the beech are destroyed by the ravages of this 

 fungus. Not only has it been found to grow on her- 

 baceous plants, such as Sempervivum, Clarkia^ and 

 many others, but it habitually attacks the seedlings 

 of many timber trees, such as, for instance, those of 

 the spruce and silver firs, the Scotch pine, the Austrian 

 and Weymouth pines, the larch, the maples, and par- 

 ticularly those of the beech. 



It is obvious that this makes the question of com- 

 bating this disease a difKcult one, and the matter is by 

 no means simplified when we learn that the fungus 

 can live for a long time in the soil as a saprophyte, 

 and apart from the seedlings. In view of all the facts, 

 let us see, however, if anything can be devised of the 

 nature of precautionary measures. It must at least 

 be conceded that we gain a good deal by knowing so 

 much as we do of the habits of this foe. 



In the first place, it will occur to everybody never 

 to use the same seed-bed twice ; but it may be added 

 that this precaution need not be taken as applying to 

 anything but seeds and seedlings. Young plants, 

 after the first or second year, are not attacked by the 

 fungus — or rather are attacked in vain, if at all — 



