26 



DWARF-SHOOTS 



[CH. 



we have what is normally a long branch with unlimited 

 growth becoming stunted to a dwarf-shoot. 



Dwarf-shoots occur normally in Betula, Populus, Pyrus, 

 Cratcegus, Prunus, Rhamnus, &c. 



Another phenomenon, equally effective in modifying 

 the aspect of the branched shoot-system, is the arrestation 

 of branches by the death of the bud at the end. 



Fig. 9. Wych Elm, Ulmus montana. Twig to the right enlarged (D). 



Every gardener knows that it is possible to produce 

 abundant branching in some plants by artificially destroy- 

 ing the terminal bud, and explains it by assuming that 

 the lateral buds, from which the flow of food-materials 

 was diverted in great part by the demands of this strong 

 bud, are now better supplied. Of course accidental 

 destructions of buds go on in Nature and produce similar 

 effects, e.g. by frost as occurs almost annually in the Elder. 

 But apart from this many plants habitually have the ter- 



