H. WORMALD 29 



there were many leaves which, with the exception that externally no 

 fungus was to be seen on them, resembled those with the Monilia 

 pustules on their surface, in that they were dark brown, curled and 

 withered. These diseased leaves were borne on the young green vegeta- 

 tive shoots, i.e. the twigs which had developed from buds during that 

 spring. At the time that observations were begun (about the middle of 

 June) the majority of the affected twigs were either wilting at the tip or 

 were quite dead for several inches from the tip downward. Others 

 showed clearly that generally, if not invariably, the damage did not 

 actually commence at the extreme tip of the damaged twig and then 

 extend backward towards the main branch, but that a discoloured (dark 

 brown) area appeared at a node bearing a dead leaf, the node being 

 situated some distance behind the apex. When the discoloured area had 

 girdled the twig the transpiration current became arrested and the 

 terminal portion of the twig thus becoming flaccid began to wilt and the 

 leaves to flag; this flaccidity caused the soft green tip of the shoot to 

 become more or less pendant and the curve produced is generally a 

 characteristic feature of the diseased twigs (see PI. VII, Fig. 1). 



At a later stage the whole of that portion distal to the node where 

 the attack originated is dark brown and withered and the discoloration 

 extends downwards for a short distance below that node, the lower 

 limits of the diseased tissues being distinctly marked off by the con- 

 trasting colours of the dead and living parts. As desiccation of the 

 diseased tips becomes more pronounced the affected tissues indurate and 

 the curved condition of the shoots persists through the winter. Since the 

 shoots are often attacked quite early in the season the leaves wither 

 before the absciss layer is developed and so remain on the tree after 

 the normal leaves have fallen. These dead twigs with their persistent 

 withered leaves may easily be recognized during the winter and early 

 spring (PI. VIII, Fig. 4). 



The injury results in the production of gum which in many cases 

 oozes out through the bark and appears at the surface as a rounded drop 

 which hardens on exposure to the air (see Pi. VII, Fig. 2). 



Instances were observed where a twig had been attacked through two 

 nodes; thus, in the example shown in Fig. 2 the terminal portion had 

 been killed by a girdling lesion at a short distance behind the apex, below 

 this being a healthy portion followed by another diseased area at a lower 

 node. 



In addition to the newly killed shoots the affected trees usually bore 

 a number of dead twigs which, from their situation on the branches, 



