THE SUNDEWS. 31 



is not in itself very extraordinary, but when we dis- 

 cover that these hairs, or tentacles, can be moved in 

 a particular direction in response to some exciting 

 cause, we have to deal with a phenomenon by no 

 means common in plant life, and we naturally become 

 curious to discover the cause. When any object, 

 living or dead, comes in contact with one of these 

 tentacles it commences to bend over towards the 

 centre of the leaf (fig. 3). The power of responding 

 to irritation, moreover, is not confined to the single 

 tentacle which has been touched, for it possesses the 

 capacity of communicating with the surrounding 

 tentacles, and they also bend over, as if in sympathy 

 with and to assist their companion. The minute 

 fragment of a human hair y^g-th of an inch in length, 

 laid upon a gland, has been shown to be sufficient to 

 excite a tentacle to bend over. Minute particles of 

 glass, chalk, and other inorganic substances, placed on 

 the glands of the outer tentacles, will cause them to 

 bend. So also will small fragments of meat, and 

 minute drops of stimulating fluids. When a tentacle 

 is touched three or four times it will also bend, but 

 not when only touched once or twice, although the 

 sustained pressure of a gnat's foot is sufficient to 

 produce the movement. After remaining bent down 

 for some time the excited tentacles again slowly 

 return to their original erect position. This return is 

 much more speedy when an inorganic body has been 



