CONCLUSION. 231 



ever, fall into the unfortunate habit of many workers in the 

 field of comparative psychology that of withholding such a 

 statement of the facts as will enable one to mark them off from 

 the inferences of the observer. 



"We arrange the activities of the wasps that we have studied 

 into two groups, Instincts, and Acts of Intelligence, it being 

 understood that these classes pass by insensible stages into each 

 other, and that acts that are purely instinctive when performed 

 for the first time, are probably in some degree modified by in- 

 dividual experience. In this classification the question of origin 

 is not considered. The facts are grouped under the two heads, 

 the inferences that they warrant being left for later considera- 

 tion. Under the term Instinct we place all complex acts that 

 are performed previous to experience and in a similar manner 

 by all members of the same sex and race, leaving out as non- 

 essential, at this time, the question of whether they are or are 

 not accompanied by consciousness. Under Intelligence we 

 place those conscious actions which are more or less modifiable 

 by experience. It is this power that enables an insect to seek, 

 accept, refuse, choose, to decline to make use of this or to turn 

 to account some other thing. Many writers prefer the term 

 Adaptation for these activities and it possesses certain advant- 

 ages. With these definitions in mind, let us group the activities 

 of wasps under the two heads. 



Instinct. 



With the Pelopaeiis wasps we were present on several occa- 

 sions when the young emerged from the pupa case and gnawed 

 their way out of the mud cell. They were limp and their wings 

 had not perfectly hardened, and yet when we touched them 

 they tried to attack us, thrusting out the sting and moving the 

 abdomen about in various directions. These movements were 

 well directed, and, so far as we could observe, quite as perfect 

 as in the adult wasp. Stinging, then, is an instinctive act. 



The particular method of attack and capture practiced by 

 each species in securing its prey is instinctive. Ammophila, 



