262 SAGACITY AND MORALITY OF PLANTS. 



(assisted by the appeal made to their generally 

 correct sense of colour by the bright red of the 

 organs) into alighting upon the leaves — almost feel 

 that nothing less than an Act of Parliament ought 

 to be introduced to put an end to such insidious 

 cruelty ! 



These tentacles are totally unaffected if particles 

 of sand or any other inorganic substance is placed 

 upon the leaf, and they never notice or respond 

 even to drops of water. This fact raises their char- 

 acter for instinctive sagacity in knowing what is 

 harmful or unnecessary to them, as well as what is 

 good in the shape of animal food. To the pattering 

 of raindrops the tentacles must be well accustomed, 

 and occasionally the wind will carry grains of sand 

 and earth to them, and cover them with dust. In 

 this way the tentacles have gained practical experi- 

 ence as to what is good for them and what is not. 



These delicate, highly -organised glands or ten- 

 tacles are merely hairs (common to the leaves of 

 most plants) which have been gradually differentiated 

 into their present structures and functions. The 

 hairs on the stems and leaves of plants are capable 

 of wonderful modification. Sometimes they are 

 stiffened into defensive prickles, as in the Goose- 

 berry ; at others they are converted into stings as in 

 the Nettle. In the Nottingham Catch-fly and other 

 plants they secrete a viscid fluid to prevent ants and 

 other creeping insects from climbing the flower-stem. 



