108 LIFE OF 



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

 see how high in the scale of organisation a plant may 

 rise, when we look at one of the more perfect tendril- 

 bearers. It first places its tendrils ready for action, as a 

 polypus places its tentacula. If the tendril be displaced, 

 it is acted on by the force of gravity, and rights itself. It 

 is acted on by the light, and bends towards or from it, 

 or disregards it, which ever may be most advantageous. 

 During several days the tendrils, or internodes, or both, 

 spontaneously revolve with a steady motion. The tendril 

 strikes some object, and quickly curls round and firmly 

 grasps it. In the course of some hours it contracts into 

 a spire, dragging up the stem, and forming an excellent 

 spring. All movements now cease. By growth the 

 tissues soon become wonderfully strong and durable. The 

 tendril has done its work, and has done it in an admirable 

 manner." 



The labour of revising the successive editions of the 

 " Origin of Species," together with prolonged ill-health, 

 delayed the fulfilment of the promise given in that work, 

 that the facts upon which it was based should be pub- 

 lished. It was not till 1868 that the first instalment, 

 " The Variation of Animals and Plants under Domesti- 

 cation," was given to the world, in two large volumes, 

 with numerous illustrations. The author's design was to 

 discuss in a second work the variability of organic beings 

 in a state of nature, and the conversion of varieties into 

 species, the struggle for existence and the operation of 

 natural selection, and the principal objections to the 

 theory, including questions of instinct and hybridisation. 

 In a third work it was intended to test the principle of 



