368 DWIGHT E. MINNICH 



brief, temporary condition, but was probably a more or less 

 permanent feature of this animal's behavior. 



The second class of animals includes those whose average de- 

 flections were small in both directions. The results obtained 

 here are attributable to either of two causes : 



a. The bee varied its turning from right to left, so that on an 

 average, one tendency nearly or quite balanced the other. 



b. The bee exhibited little or no tendency to turn either to the 

 right or to the left. 



An example of the first type is seen in the records of bee no. 36, 

 figure 7. In its first set of trials (a, 1, 2) this animal turned 

 sometimes to the left, sometimes to the right, so that the result- 

 ant average deflection was but 0.79°/cm. to the left. Similarly 

 in the second set of trails {b, 1,2), the average deflection amounted 

 to only 1.94°/cm. to the right. The second type of this class is 

 illustrated by bee no. 134, figure 8. This animal showed no pro- 

 nounced tendency to turn either to the right or left. The aver- 

 age deflection for each set of records was, therefore, small, being 

 only 1.527cm. to the left for the first set (a, 1, 2, 3) and 1.227cm. 

 to the left for the second set (b, 1, 2, 3, 4). 



In the third class of bees are to be found those which, although 

 they exhibited fairly uniform behavior in a single set of trials, 

 varied widely in different sets. For example, bee no. 82, in its 

 first record (fig. 8, 82, a) showed a pronounced deflection which 

 averaged 5.81°/cm. to the left. In its second set of 'trials (fig. 

 8, 82, b, 1, 2, 3, 4), on the contrary, it showed little tendency to 

 turn, and the average deflection was but 0.65°/cm. to the left. 

 An even more striking case of variation, however, was afforded 

 by bee no. 63. In a single record of fifty-three seconds' duration 

 (fig. 8, 63, a) this animal deflected, on the average, 5. 58°/cm. to 

 the left. Approximately two hours later, in a record of sixty 

 seconds' duration (fig. 8, 63, b), the same animal exhibited an 

 even greater average deflection in the opposite direction, viz., 

 7.50° /cm. to the right. The range of variation presented by 

 these two records is no less than 13.08°/cm. 



In a uniform, non-directive light field, therefore, many bees 

 exhibit a fairly constant tendency to turn toward a given side, 



