146 CELL INTELLIGENCE THE CAUSE OF EVOLUTION 



with a hot iron. Later the most distressing symptoms 

 arise in other parts of the body, which not uncommonly 

 involve the contraction of the muscles of the jaw and 

 other indications which are similar to those to be ob- 

 served in the case of lock-jaw. In one instance it was 

 nine days before the unhappy individual was free from 

 pain and discomfort. In such a case as this it would 

 seem that a huge amount of unnecessary suffering is in- 

 volved. It is possible to protect a plant from attack as 

 can be seen in many cases without adopting such brutal 

 methods. 



"Self-defense has been carried to a fine art among 

 desert plants, especially the cacti. An array of spines is 

 of course an admirable means of preventing an attack, 

 but many species have carried the matter a good deal 

 further. In some kinds of prickly pear they have minute 

 barbs on their spines and if any animal should even brush 

 up against them the spines hold on firmly when driven 

 into the flesh. They are loosely attached so. that the un- 

 happy creature takes away a large number of spines 

 when he withdraws. These remain to produce festering 

 wounds. Another cactus which adds singular hooked 

 spines to the straight variety is called "The Wait-a-bit 

 Plant." The hook holds the clothes Or flesh and mean- 

 while the sharp straight spines do deadly work. 



"It is of course well known that a certain number of 

 species find it needful to capture insects in order that 

 thev may supplement their supply of nitrogenous food. 

 In most of the schemes the unhappy victim is doomed to 

 undergo the torture of a lingering death. Very rarely is 

 the insect killed at once. First of all let us consider the 

 case of the Darlingtonia, a plant which usually catches 

 winged insects. The flies are lured by honey secretion 

 to enter the hooded process at the top of the pitcher-like 



