372 DWIGHT E. MINNICH 



The above experiment was carried out on five bees. In gen- 

 eral, all of these animals looped more or less markedly toward the 

 functional eye as they crept toward the light source. This tend- 

 ency, moreover, was not confined to the period immediately 

 subsequent to the operation of blackening the eye, as the experi- 

 ment clearly demonstrates. The first records of these bees with 

 their left eyes blackened were taken in the evening between 6 

 and 7 p.m. No further tests were made until the following day 

 at 11:30 A.M. Yet the behavior at the end of this seventeen- 

 hour period was practically the same as it had been before. One 

 bee, it is true, showed considerable improvement. In the other 

 four animals, however, the two sets of records were indistinguish- 

 able. In the absence of experience, therefore, the performance 

 of circus movements remains a permanent feature of behavior. 



Of the five bees tested, the most pronounced and uniform exhi- 

 bition of circus movements was displayed by bee no. 5. Its 

 records are almost diagrammatic in their close approximation to 

 the theoretical expectation. Records of this animal are repro- 

 duced in figure 9. 



Not all of these animals, however, yielded such striking results. 

 Some individuals were found which manifested little or no tend- 

 ency to deviate toward the functional eye, except in the area 

 immediately beneath the lamp, where the illumination was es- 

 sentially non-directive. Thus, bee no. 4, with its right eye black- 

 ened, circled toward the left in the usual manner. But a few 

 hours later, when the black had been removed from the right 

 eye and the left eye painted over, it exhibited little or no tend- 

 ency to circle toward the right (fig. 10, B). The explanation 

 at once suggests itself, that in such cases the eye was imperfectly 

 covered, and hence not absolutely free from stimulation. This 

 may be correct. As will be shown later, however, there are also 

 a variety of other circumstances which might account for such 

 behavior. 



The tendency to circle toward the blackened eye was not fre- 

 quently encountered in the reactions of bees to directive light. 

 No instance of it occurred in the experiment described above, al- 

 though it was occasionally met with in other experiments. A 



