Reflexes, Instincts, and Intelligence 639 



certain small simple insects (Poduridae) which he found living in the sand 

 beaches of Long Island to be determined as follows : 

 " I. General movements. 



A. Running: oxygen, lack of (?). 



B. Springing: currents of air, or jarring of substratum. 

 II. Special locomotive movements. 



1. Whirling: touch, water. 



2. Descent into the sand : touch, water, gravity. 



3. Rising from sand: water, gravity. 



4. Running up stones: gravity, light. 



5. Moving toward wind: current of air. 



6. Leaping into air: gravity, currents, oxygen-need." 



Most insect behavior is likely to be due to several or many stimuli 

 acting at once so that the behavior itself is the complexly formed result- 

 ant of various reactions. And in most cases it is difficult or impossible 

 to analyze it into its component parts. Insects are really very complexly 

 organized animals and their physiology and psychology is a synthesis of 

 many elements. But occasionally an insect species may be found which lends 

 itself fairly readily to the analytical study, by experimental methods, of its 

 behavior. Or other species may be found which reveal at one or another 

 stage in their life a period when some one reaction or reflex is all-dominant 

 and its relation to its special stimulus is plainly revealed. Two examples 

 of the determination of tropismic behavior on the part of highly specialized 

 insect species which have come under my own observation may be described. 



In the course of some experiments on the sense reactions of honey-bees, 

 I have kept a small community of Italian bees in a glass-sided, narrow, high 

 observation hive, so made that any particular bee, marked, which it is de- 

 sired to observe constantly, cannot escape this observation. The hive con- 

 tains but two frames, one above the other, and is made wholly of glass, 

 except for the wooden frame. It is kept covered, except during observation 

 periods, by a black cloth jacket. The bees live contentedly and normally 

 in this small hive, needing only occasional feeding at times when so many 

 cells are given up for brood that there are not enough left for sufficient stored 

 food-supplies. One spring at the normal swarming time, while standing 

 near the jacketed hive, I heard the excited hum of the beginning swarm 

 and noted the first issuers rushing pellmell from the entrance. Interested 

 to see the behavior of the community in the hive during such an ecstatic 

 condition as that of swarming, I lifted the cloth jacket, when the excited 

 mass of bees which was pushing frantically down to the small exit in the 

 lower corner of the hive turned with one accord about face and rushed 

 directly upward away from the opening toward and to the top of the hive. 

 Here the bees jammed, struggling violently. I slipped the jacket partly on; 



