A NATURALIST IN BRAZIL 



consist of metamorphosed leaves, while the true leaves are retarded 

 in their development. Longer and longer grow the shoots, until the 

 wind catches them and sways them to and fro. If no other stem is as 

 yet within reach, the claws retract themselves and the leaves proceed 

 to grow. But the urge is not appeased ; once more fresh claws appear 

 at the tip of the creeper, and the plant swings to and fro through 

 an ever-widening arc. At last the wind blows the hanging shoot 

 against another tree-trunk; immediately the claws enter into the 

 bark, roots grow out of them, and the liana wanders over its new 

 arboreal support, drawing after it, from the old one, a long festoon. 



The twining lianas are those in which the stem itself embraces the 

 supporting tree, winding round it like a snake as it reaches upwards. 

 The virgin forest is full of such lianas, and it is these plants which 

 give it such a strange and unfamiliar appearance. Many lianas begin 

 by climbing up quite a slender sapling, or a reed, or even a grass- 

 stem, from which they reach the trunk of a tree. Here they obtain 

 the needed support, and the stem can now grow thicker and thicker ; 

 but it retains its twists and turns, under which the fragile supporting 

 plant completely disappears. In the end the convolutions press 

 against one another, and a twisted cable results, as thick as a man's 

 arm (Fig. 3, Plates 15 and 24). These are known as "bush cables." 

 They enhance the impression of a stealthy mechanism, of the latent 

 energy of the forest. 



The vegetable life of the forest would seem still more uncanny if 

 our eyes could follow the gradual movements of the plants. For the 

 shoots of the lianas do not grow upwards only, but in a slanting 

 direction, and even horizontally outwards, and as they grow their 

 tips revolve until they have described a complete circle. This 

 circling movement of the tip of the shoot has been likened to that 

 of the hand of a clock. If one lays a sheet of paper under the shoot 

 one can follow the movement of the tip by watching the shadow. 

 On an average, the shoot takes one to two hours to complete the 

 circle. 



The newer technical methods reveal this movement still more 

 vividly. Photographs of a climbing plant are taken on a film with 

 short intervals between the exposures. If the positive of the film is 

 now run through a projector, the happenings of hours are reduced 

 to minutes, and the movements of the plant are plainly visible. The 

 shoots appear to move like the arms of an octopus seeking its prey. 

 Now one strikes against a tree-stem, and forthwith it throws a lasso 

 round it, while the rest of the shoot curls up like a corkscrew. The 



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