160 HOUSE, GARDEN, AND FIELD 



almost straight for the greater part of its length. What 

 is less easily seen is that the tip revolves steadily until it 

 has caught hold, sweeping round and round as if exploring. 

 The coil into which the tendril is thrown after it has secured 

 itself is not a simple but a double coil, half being right- 

 handed, and the other half left-handed ; a short uncoiled 

 piece unites the two. Why is the coil reversed ? (9) 



Vines and passion-flowers are excellent examples of 

 tendril-bearers, but these can seldom be examined except 

 in greenhouses. You can, however, easily procure the 

 tufted vetch (Vicia cracca) which runs in the hedges, and 

 this is well worthy of study. Charles Darwin, in his 

 admirable book on Climbing Plants, which first incited 

 naturalists to take special notice of their contrivances, 

 tells us about many other tendril-bearers, and among the 

 rest he describes the Virginia creeper. You can read, or 

 better still, see for yourselves how the tendrils of the 

 Virginia creeper seek the shade, because there they are most 

 likely to find a surface of support ; how the tips of the 

 branched tendrils, as soon as they touch the bricks or 

 plaster, swell, turn red, and form adhesive cushions, which 

 are pressed into all the inequalities of the surface ; how 

 the tendrils coil themselves as soon as they have got a 

 firm hold, and so drag up the branch ; and how they hold 

 fast for years, long after they are dead. None of the 

 books of the great naturalist illustrate better than this one 

 how the true student of nature will discover in the com- 

 monest plants and animals beautiful adaptations which 

 had escaped the notice of all the generations of men. Even 

 more worthy of study than the contrivances themselves 

 are the qualities of mind and character which make a 

 keen observer and a sagacious interpreter. 



The advantages got by climbing are very obvious. The 

 climber is enabled to throw the burden of its support 

 upon other plants ; it forms little wood and grows fast. 

 In England there is only one climbing plant which can 

 ascend tall trees ; name that one. In hot countries there 



