INSTINCTS 159 



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 desired to observe constantly, can not escape this obser- 

 vation. The hive contains 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. Tbe 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. Last spring 

 at the normal swarming time, while standing near the jacketed hive, 

 I heard the excited hum of a 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 ; the 

 ones covered turned down; the ones below stood undecided; I dropped 

 the jacket completely; the mass began issuing from the exit again; 

 I pulled off the jacket, and again the whole community of excited bees 

 flowed — that is the word for it, so perfectly aligned and so evenly 

 moving were all the individuals of the bee current — up to the closed top 

 of the hive. Leaving the jacket off permanently, I prevented the issuing 

 of the swarm until the ecstasy was passed and the usual quietly busy 

 life of the hive was resumed. About three hours later there was a 

 similar performance and failure to issue from the quickly unjacketed 

 hive. On the next day another attempt to swarm was made, and after 

 nearly an hour of struggling and moving up and down, depending on 

 my manipulation of the black jacket, most of the bees got out of the 

 hive's opening and the swarming came off on a weed bunch near the 

 laboratory. That the issuance from the hive at swarming time depends 

 upon a sudden extra-development of positive heliotropism seems obvious. 

 The ecstasy comes and the bees crowd for the one spot of light in the 

 normal hive, namely, the entrance opening. But when the covering 

 jacket is lifted and the light comes strongly in from above — my hive 

 was under a skylight — they rush toward the top, that is, toward the light. 

 Jacket on and light shut off from above, down they rush; jacket off 

 and light stronger from above than below and they respond like iron 

 filings in front of an electromagnet which has its current suddenly 

 turned on. 



