366 DWIGHT E. MINNICH 



distance. Each animal was subjected to two sets of trials, an 

 hour or so apart. Usually a single trial only constituted a set. 

 In case the bee quickly encountered the side wall of the light 

 chamber, however, or exhibited unusual variabihty in its be- 

 havior, additional trials were made. The aggregate duration of 

 the trials of each set varied considerably, even in the same animal. 

 Sometimes they were as short as thirty seconds; again, as long as 

 two minutes. The average was in the neighborhood of thirty 

 to sixty seconds. Preliminary to each trial, the bee was exposed 

 to light until aroused to active creeping. The illumination used 

 throughout in experimenting with normal bees was 957 mc.^ 



The average deflection to the right or to the left has been 

 computed for each set of records thus obtained, and the results 

 of these computations presented in table 2 (appendix), columns B 

 and C. On the basis of these data, the fifty-two bees experi- 

 mented upon may be classified into three groups : 



1. Bees whose average deflection in both sets of trials was over 

 2° /cm. and in the same direction. 



2. Bees whose average deflection in both sets of trials was 

 small. 



3. Bees whose average deflection in the two sets of trials varied 

 widely, either in magnitude or direction, or in both. 



The first class is composed of animals which exhibited a more 

 or less pronounced tendency to turn in a constant direction (right 

 or left). These animals, 29 in number, comprised 56 per cent 

 of the total 52 bees. Fourteen of these were chiefly right-handed 

 in their turns; 15, left-handed. In 14 of the 29 bees, or 27 per 

 cent of the total number, the average deflections exceeded 4° /cm., 

 while in 6 individuals, or 12 per cent, it rose to over 8°/cm. Sim- 

 ilar right and left-handed tendencies of locomotion in non-direct- 

 ive light have been reported by Walter ('07) for planarians and 

 by Patten ('14) for the blowfly larva. A typical example of this 

 behavior in bees is illustrated in figure 7, bee no. 101. In its first 

 trial (fig. 7, 101, a), this animal showed an average deflection of 

 7.11°/cm. to the left, and in the second trial (fig. 7, 101, b), a sim- 

 ilar deflection of 6.10°/cm. Since these records were made nearly 

 an hour apart the left-handed tendency was not the result of a 



