COHSGIOUSflESS 



PLANTS, it has been vaguely asserted, differ from animals 

 by not having the power of movement. Rather should 

 it be stated that plants acquire and display this power when 

 it is to their advantage. This will be found to be of com- 

 paratively rare occurrence, as they are affixed to the ground, 

 and food is brought to them by the air and rain. Evidence 

 of the very high position a plant may attain in the scale of 

 organization may be seen when we look at one of the more 

 perfect tendril-bearers. As a polypus adjusts its tentacula 

 for action, so a plant places its tendrils. If the tendril be dis- 

 placed, it sets to work to right itself. Acted on by the light, 

 it bends towards or from it, or disregards it altogether, which- 

 ever course may be the most advantageous. For several 

 days the tendrils or internodes of the plant, or both, sponta- 

 neously or otherwise revolve with a steady motion. But 

 should they strike some object, they curl quickly around it, 

 grasp it with wonderful firmness, and in the course of a few 

 hours contract into spirals, dragging up the stems, and form- 

 ing most excellent springs. All external movements now 

 cease, and by growth the tissues soon become surprisingly 

 strong and durable. 



Such a movement, as has just been considered, is a widely 

 prevalent one in plants, and is essentially of the same nature 

 as that of the stem of a climbing plant, which successively 

 bends to all points of the compass, so that the tip is made to 

 revolve. This movement has been called revolving nutation 

 by some writers, and circumnutation by others. In the case 

 of the circumnutating movement of the tip of the radicle of 



