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Transactions. 



to the weight of the plant, and lateral strains due to the action of the wmd. 

 Further, the whole plant is thus adapted to maintain its position upon the 

 loftiest supports in the forest. 



(ii.) Tendril-anatomy : The structure of the tendril shows how in its 

 stages of development it is admirably suited for performing its functions 

 (fig. 10). In its earliest stages the best position is an extended one, which 

 will increase its chances of coming into contact with a support, and the 

 arrangement of tissues is such as to favour the maintenance of this position. 

 The collenchyma forms a band near the periphery of the tendril, and the 



Fia. 10. — Tetrapathaea australis. Diagrams of tendril, showing development of me- 

 chanical tissue, col, collenchyma; ep., epidermis; sec. wd., secondary- 

 wood; St., stsreome; vase, bund., vascular bundle. 



vascular bundles are distributed in a ring at a considerable distance from 

 the centre. Then at a later stage the development of stereome is equally 

 suitable. On the future convex side, where growth and expansion of the 

 tissues is essential, stereome is at first absent ; but on the concave side 

 it develops rapidly, and thus by its resistance to tension it prevents the 

 tendril being unrolled from the support. Finally, the injury to structures 

 from external pressure is prevented by the ring of collenchyma, which is 

 a constant character of the tendril-structure.. 



III. METHODS OF GAINING SUPPORT, 

 1. Fuchsia Colensoi. 



Seedlings are numerous in the forest throughout well-drained but moist 

 positions. 



The primary shoot does not usually grow more than 35 cm. high without 

 support, for lateral shoots are early given off and tend to drag the plant 

 down to the ground. However, it often comes into contact with some 

 support against which it rests. Should the support be very low, the Fuchsia 

 branches, which project at right angles, soon spread over it. Shoots stand 

 up from the top of the support, and, supporting themselves, can reach a 

 height of fuUv 50 cm. ; other shoots project from the sides of the support, 

 and thus a new support is often reached. 



