Reflexes, Instincts, and Intelligence 655 



ing her regular routine. We allowed her to carry in one grasshopper to 

 establish her normal method of procedure, and found that, bringing it on 

 the wing, she dropped it about six inches away, ran into the nest, out again, 

 and over to the grasshopper, which she straddled and carried by the head 

 to the entrance. She then ran down head first, turned around, came up, 

 and, seizing it by the head, pulled it within. On the following day, when 

 she had brought the grasshopper to the entrance of the nest, and while she 

 was below, we moved it back five or six inches. When she came out she 

 carried it to the same spot and went down as before. We removed it again 

 with the same result, and the performance was repeated a third and a fourth 

 time; but the fifth time that she found her prey where we had placed it, she 

 seized it by the head and, going backward, dragged it down into the nest 

 without pausing. On the next day the experiment was repeated. After 

 we had moved the grasshopper away four times, she straddled it and carried 

 it down into the nest, going head foremost. On the fourth and last day cf 

 our experiment she replaced the grasshopper at the door of the nest and ran 

 inside seven times, but then seized it and dragged it, going backward into 

 the nest. 



"How shall this change in a long-established custom be explained except 

 by saying that her reason led her to adapt herself to circumstances? She 

 was enough of a conservative to prefer the old way, but was not such a slave 

 to custom as to be unable to vary it." 



Morgan believes that a fair weighing of the evidence put forward by 

 Fabre and the Peckhams leads one to conclude that "among the solitary 

 wasps and mason bees the behavior, though founded on instinct, is in large 

 degree modified by intelligence." In the behavior of the Ammophilas ob- 

 served by Williston in Kansas and the Peckhams in Wisconsin, which used 

 a small stone to tamp down and level off the soil filling the nest hole, Mor- 

 gan sees "an intelligent behavior rising to the level to which some would 

 apply the term rational. For the act may be held to afford evidence of the 

 perception of the relation of the means employed to an end to be attained, 

 and some general conception of purpose." 



After all, to attempt to make sharp distinctions between reflexes and 

 instincts and between instincts and intelligence is bound to lead to more or 

 less verbal quibbling. I believe that the distinctions will be more and more 

 effaced with increasing knowledge of animal behavior on our part. And on 

 the whole it seems to me quite fair to say that our present point of view, in 

 the light of the increasing evidence for mechanical or physico-chemical 

 explanations of insect actions, should be that of the believer in the simpler 

 and less anthropomorphic explanations of behavior, i.e., the explanation of 

 tropisms and reflexes, and complex and coordinated series of them, which 

 may be termed instincts. 



