314 TRANSACTIONS AND PROCEEDINGS OF THE [Sess. lxiv. 



it has not been definitely ascertained what parasitic fungus 

 is the cause of them. 



The Craighall broom-bearing larcli is one of a small 

 collection of trees forming an open straggling plantation 

 on the south slope of a sheltered glen. The ground 

 drainage is good, and the plant covering consists of 

 Calluna, grasses, and other moorland plants, with an 

 occasional patch of rushes. A large number of the trees 

 showed canker spots due to Pcziza Wilkommii, and also 

 leaves geniculate from the attacks of CJicrmcs laricis. The 

 tree bearing the broom was no exception, the broom in 

 particular showing .an abundance of Pcziza disks and 

 (7/ier?wes-attacked needles. One half of the broom — that 

 half worst infected with Pcziza — was dead, the other half 

 was in very active vegetation. 



The broom (Plate I.) was of large dimensions, measuring 

 15 feet in circumference and quite 4 feet in height. This 

 large size, in conjunction with its bushy growth and vivid 

 green colour when in foliage, made it a conspicuous object 

 when seen from a distance. It had diverted to itself the 

 greater share . of the supplies, so that the parts above it 

 were stunted. The leader was only about four feet in 

 height above the point of origin of the broom, and was so 

 slender that it had been broken across in some storm a 

 few years ago and was hanging down on the east side in 

 a moribund condition, still attached, however, by a band of 

 wood and bark, showing in section a few imperfect rings 

 and some attempt at occlusion. A branch having a 

 common origin with that which bore tlie broom was also 

 depauperised. It was, however, quite normal, except that 

 it showed Pcziza disks and geniculate needles. A lateral 

 of the same whorl, but arising on tlie o})posite side of tlie 

 axis, was growing vertically as a leading shoot, and had 

 attained to a height of 10 or 12 feet, and a thickness 

 in proportion. -Just beneath the origin of tliis leader, the 

 axis was badly cancerous, as evidenced by the copious 

 development of Pcziza disks. 



The tree was al)Out sixteen years old, and the l)room 

 development evidently commenced in a lateral bud about 

 the seventh or eighth year. The branch was 5 feet 

 from the giound, and at that heiglit the ti'unk measured 



