Reflexes, Instincts, and Intelligence 653 



of them. We have doubtless overlooked some activities that should come 

 under this head, as we have not made a thorough study of any sufficient 

 number of species to make a final settlement of the matter. For conve- 

 nience we give the eight primary instincts that we have enumerated in tabular 

 form: 



INSTINCTS 



1. Stinging. 



2. Taking a particular kind of food. 



3. Method of attacking and capturing prey. 



4. Method of carrying prey. 



5. Preparing nest and then capturing prey, or the reverse. 



6. The mode of taking prey into nest. 



7. The general style or locality of nest. 



8. The spinning or not spinning of a cocoon, and its specific form 



when one is made. 



"Intelligence. It is obviously more difficult to distinguish actions of this 

 class than of the other. One must be familiar with the normal conditions 

 of the insects in question before he is able to note those slight changes in 

 the environment that offer some opportunity for an adaptation of means to 

 ends, or before he is competent to devise experiments which will test their 

 powers in this direction. 



"We find two classes of intelligent actions among the Hymenoptera 

 which are sufficiently distinct to be considered separately, although, like all 

 natural groups, they grade into each other. The first of these includes 

 those actions that are performed by large numbers in a similar fashion under 

 like conditions, while in the second class each act is an individual affair, as 

 where a single wasp, uninfluenced in any way by the example of those about 

 it, displays unusual intelligence in grappling with the affairs of life. Exam- 

 ples of the first class are found in such modifications of instinct as are shown 

 by Pelopaeus and other wasps in the character of their habitations. Pelopaeus, 

 instead of building in hollow trees or under shelving rocks, as was the ancient 

 custom of the race, now nests in chimneys, or under the eaves of buildings. 

 We have found T. rubrocinctum taking advantage of the face of a straw 

 stack that had been cut off smoothly as the cattle were fed through the 

 winter. The same power of adaptation is shown by Fabre's experiment 

 with Osmia, in which he took two dozen nests in shells from a quarry, where 

 the bees had been nesting for centuries, and placed them in his study along 

 with some empty shells and some hollow stems. When the bees came out, 

 in the spring, nearly all of them selected the stalks to build in as being better 

 suited to their use than the shells. All of these changes are intelligent adap- 

 tations to new modes of life, serving to keep the species in harmony with its 



