374 



Bulletin 164. 



the large branches where a diseased cluster of leaves has been 

 attached. Figure 65 shows the condition often called gummosis. 

 Defoliation of the entire tree does not necessarily mean the 

 death of the tree ; but it does mean the death of many twigs, 

 and lessened vitality. New buds, or rather some of the sleep- 

 ing or dormant buds open and the tree attempts to supply itself 

 with new and healthy foliage. It is very seldom that this fresh 

 foliage is badly affected by the curl ; and it is possible to account 



66. — a^ healthy twig; b and c^ twigs in which the leaf -curl fu7ig us is win- 

 tering ; and dy twig killed by the fungus. 



for w^hatever curl is now evident as having come directly from 

 diseased buds or twigs. 



The new shoot growing out from a diseased terminal bud may 

 grow entirely out of the disease, but the swollen part remains 

 below\ Thus, when the season's growth is done and the autumn 

 at hand, these sw^ollen areas may mark out the recovery of shoots ; 

 but the}^ also indicate where the fungus rests ; and they are 

 warnings of danger for another season. Figure 66. b and <:, 



