V] EPICORMIC BRANCHES 57 



The three sets of cases here postulated are quite 

 different, and the difference in terminology is justified 

 by the facts as to the origin of the " Epicormic branches," 

 " Stool-shoots " and " Suckers " respectively. Only in the 

 sense that the buds giving rise to them are out of their 

 proper order in the symmetry of the tree are they to be 

 referred to as adventitious ; but the manner of their being 

 so is quite different in all three cases. 



If we carefully examine tlie place of origin of the buds 

 giving rise to epicormic branches, on a tree trunk or 

 limb, it may often be seen that they arise from the crevice 

 behind the crest of an arcuate cushion, which slightly 

 projects from the surface of the bark : this cushion is all 

 there is left to show where, years before when the limb 

 or trunk was a mere twig, a leaf-scar existed, and the 

 crevice behind it was a leaf-axil. In other cases the 

 cushion represents the inequality in the surface of the 

 bark due to the pressures exerted by a thickening axillary 

 branch. In the former case the bud is really arising in 

 an old leaf-axil : in the latter it is arising from the ex- 

 treme base of what was years ago an axillary branch. 



But what is a bud, now about to develope a shoot, 

 doing in such a position ? why did it not long ago grow 

 out to a shoot, which, judging from the age of the 

 parts concerned, should now be a stout branch many 

 years old ? 



The comparison of large numbers of cases points to 

 the following as the explanation. When, years before, 

 the bud in the leaf-axil, now only indicated, should have 

 developed into a shoot, the competition for water and 

 food of other buds in the neighbourhood resulted in its 

 partial starvation, so that it was unable to put forth even 

 so much as a dwarf-shoot, and it remained a bud, but did 

 not die. 



