PHOTIC REACTIONS OF HONEY-BEE 365 



looping now to the right, now to the left, and finally turning al- 

 most directly away from the light. In a second trial at 4:14, it 

 exhibited a somewhat similar response (fig. 6, 2). One minute 

 later, the animal was subjected to still a third trial, being started 

 on this occasion some 30 cm. nearer the light. This time it ori- 

 ented and moved in a fairly direct course toward the source of 

 illumination (fig. 6, 3). What the temporary, inhibiting factors 

 were which produced these very atypical responses could not be 

 ascertained. In all other respects this bee was quite indistin- 

 guishable from the other individuals in the experiment. This 

 example, however, shows that even the constant response of the 

 bee to directive illumination is not free from abrupt and appar- 

 ently inexplicable departures. 



3. Non-directive light 



The behavior of bees in non-directive light is no less charac- 

 teristic than that in directive illumination. Since all quantita- 

 tive experiments on circus movements were conducted in non- 

 directive light, an intimate acquaintance with the behavior of 

 normal animals under the same conditions was necessary. Every 

 bee was, therefore, subjected to several trials in non-directive 

 light before having one eye blackened. 



It was a matter of continual observation that a bee creeping in 

 the directive light area ceased to move in a straight course upon 

 reaching the area near and immediately beneath the lamp. 

 Here, where the illumination was essentially non-directive, the 

 animal deflected from its former, precise path and began to loop 

 in a constant or varying direction (fig. 1). In other words, the 

 bee was trapped; for directly it crept away sufficiently for the light 

 to become directive again, it was forced to turn back. Thus the 

 animal continued to creep round and round in a limited area, 

 occasionally rearing on its hind legs in an abortive attempt at 

 flight, or finally ceasing locomotion to begin cleaning operations. 



In the non-directive light apparatus (fig. 2), the same tend- 

 ency to loop was manifested, only on a much more extensive 

 scale. Here the bee seldom crept in a straight line for any great 



