NOTES AND QUERIES. II5 



any pathological features carefully noted. There is rather a 

 tendency among plant-growers to accept the most evident 

 symptoms as the more important, but practical forest protection, 

 whether against insects or fungi, must be based not on the 

 study of insects or fungi alone nor of forestry alone, but on the 

 relation of all these to one another. J. W. M, 



The Occurrence of the Phomopsis Disease of the 

 Japanese Larch in Yorkshire. 



In the report of the annual excursion issued in the December 

 192 1 number of the Transactions of the Society, reference is 

 made to a disease of the Japanese larch found on the Jervaulx 

 Abbey estate in Yorkshire. The attack was first noticed in 

 1916, and it is suggested in the September 192 1 number of the 

 Transactions, that it is probably due to the fungus Phomopsis 

 Pseudotsugae. 



By the courtesy of Mr John Maughan I had an opportunity, 

 in April of this year, of making an examination of the diseased 

 trees, which are 20 years old and are growing in a plantation 

 of pure Japanese larch. The trees show patches of dead bark 

 about the size of the palm of the hand, which are most plentiful 

 in the lower part of the stem, where the branches have been cut 

 off. On removing the dead bark, which is only loosely attached, 

 a patch of dead wood is seen which is being rapidly covered by 

 the growth of callus tissue from its edges. An examination of 

 the tree showed that the cambium had been killed under the 

 dead bark, and that, in consequence, no secondary thickening 

 had taken place for several years in these areas. Traces of small 

 fungous fructifications were found in the bark, but these were in 

 a very disintegrated condition and no spores were discovered. 

 On microscopic examination numerous hyphae were found to be 

 present in the cells. 



On comparing these trees with specimens of the Japanese 

 larch known to be attacked by Phomopsis Pseudotsugae, there is 

 little doubt that the damage in the Yorkshire specimens is due 

 to this fungus. Not only are the hyphae similar, but the 

 wounds produced, and the subsequent healing process, are 

 almost identical. The absence of recognisable fructifications and 

 spores in the specimens is not surprising since the attack 



