IGU EXPEliLMKNT STATION. [Jan. 



as the sliout will outgrow it in from tliree to live years, and does 

 not seem to suti'er any serious ill effects from the trouble. 



(5) It is caused by a sudden disruption of the metabolic 

 processes of the tree, all leaf activity being suspended ; and there 

 being no normal relationship between root metabolism and leaf 

 metabolism, the new shoot is unable to properly bring into avail- 

 able form the food supplied for the nourishment of the tree. In 

 other words, th(>re is an attempt on the ]y<{vt of the leaves to cor- 

 relate their functions with a root area many times larger, and 

 consequently a pathological condition is set up within the tissue, 

 due, as has before been said, to imperfect metabolism. 



