40 TRANSACTIONS OF ROYAL SCOTTISH ARBORICULTURAL SOCIETY. 



SO in the other, and especially as regards the Douglas fir in its 

 present unfixed type. While the horticulturist has by persistent 

 endeavour, from his point of view, improved the standard of 

 almost every plant under his charge, comparatively little has 

 been done in an endeavour to improve the type of our timber- 

 trees, or even to preserve their best features. 



To attack by insects and fungi the tree is not immune, although 

 less subject than our native and longer introduced trees. In the 

 nursery, Botrytis Douglasii is responsible for the killing back of a 

 few young shoots, and Phoma Douglasii at a later stage occasion- 

 ally attacks the stems of the tree, but the real damage to be 

 guarded against is that caused by Agaricus ntelleus and Trametes 

 radiciperda, which attack the trees after being planted out in the 

 forest. On old clearings, or when underplanted in old hardwood 

 plantations, they are likely to be most destructive. Another 

 fungus, Aeciditim coruscans, which I believe has not previously 

 been observed in this country, or mentioned in scientific literature 

 as attacking the Douglas fir, I found in a few young plants in 

 the nursery some time ago. It is a species of rust-fungus, and is 

 stated by Hartig to be common on the spruce in Sweden and 

 Finland. (See Fig. 2 Plate VII.) 



As regards insect pests, the pine weevil, Hylobius abietis, 

 seems to be the only cause of damage to the tree, but with 

 proper precautions injury from this source can be easily avoided. 

 Megastigmus spermotropJuis, a species of the Cyfiipidce or Gall 

 wasps, is occasionally destructive to the seeds, but its life- 

 history is still under investigation, and it is to be hoped that 

 some means of overcoming its attack may be devised. 



The practical experience gained of the Douglas fir in this 

 country points it out as one of the most valuable timber-trees ever 

 introduced, and when its suitability for commercial purposes has 

 been fully realised, there can be no doubt it will be one of the 

 most largely planted of all our timber-trees. 



