THE INSECTS: HEXAPODA 87 



Actions which are due to the results of individually 

 acquired experience, and which are performed without reflec- 

 tion or deliberation as to the means to be employed, or knowl- 

 edge of the end to be reached, are termed intelligent actions 

 by Professor Morgan. The behavior of that particular Ammoph- 

 ila observed to make use of a stone to pound down the sand 

 over her nest may be called intelligent, using the word in 

 the sense just defined. The power possessed by the honey-bee, 

 bumblebees, and other Hymenoptera, of finding their way 

 back to the nest, often from a considerable distance, may be 

 dependent on a knowledge of the locality acquired in their 

 various trips. If so, it would be an example of an intelligent 

 action. Many of the habits of ants already described should 

 probably be included here. 



The word " intelligent " is commonly used to cover another 

 and quite different class of activities, which demand separate 

 consideration. To those activities which are guided in accord- 

 ance with a plan which takes into consideration both the ques- 

 tion of means to be employed and the end to be reached 

 Professor Morgan applies the term " rational." Thus, a man 

 in attempting to cross a swollen brook will consider the pos- 

 sibility of leaping, w r ading, or swimming across; or he will 

 look about for material to make a bridge, noting the posi- 

 tion of stones which might serve for supports, and consider- 

 ing, perhaps, the possibility of piecing together two short 

 boards to make one board long enough for his purpose. When 

 action is finally taken it is the result of a carefully consid- 

 ered plan. An example of this class of actions cannot be 

 given from the insects, as we have at present no satisfactory 

 evidence that the behavior of any insect ever rises to the 

 rational plane. 



In the discussion of this question it must not be forgotten 

 that instincts are not fixed and unalterable, but that they are 

 constantly being modified by new experiences. Therefore many 



