CHAPTER VIII. 



NON-TYPICAL SHOOTS. CLIMBING PLANTS. 



Elongated internodes Methods of climbing Ivy as a root-climber 

 Other root-climbers Scrambling plants Twining plants 

 Kevolving movements of the stem Direction of twining 

 Surface of twining stems Torsions Tendril-climbers Leaves 

 acting as tendrils Evolution of leaf-tendrils in Leguminosse 

 Stem-tendrils The Vine Behaviour of a tendril After-effects 

 on grasping tendrils Adhesion -discs on tendrils Climbing 

 methods of species of Bignonia Outgrowths on tendrils 

 Tendril-like roots Anastomosis of climbing roots Hook- 

 climbers Branch-climbers Watch-spring-like tendrils Ten- 

 drils in Vitaceae. 



WE have seen that the typical shoot is an erect structure 

 consisting of stem and branches bearing leaves and flowers 

 and appendages of that kind. There are very many cases, 

 however, where the shoot, though manifestly typical in 

 its essential nature, departs sufficiently from the normal 

 to be remarkable at once. Striking examples are found 

 among the numerous kinds of climbing plants. 



In the typical erect shoot, the principal function the 

 exposure of the leaves to plenty of light and air is 

 brought about by the primary axis being sufficiently stiff 

 and strong to support the weights of leaves, flowers and 

 fruits, in spite of the winds which tend to throw the 

 whole structure ; and we have seen several varieties, from 



