BEHAVIOR OF A PARASITIC BEE 391 



with the lower edge of the shadow it usually dropped back- 

 wards into the light (Ex. 4, 9, 17). There was no revolution 

 of the body through 180 degrees, yet this marked reversion in 

 behavior induced by contact with the shadow might well be 

 considered an example of "differential sensibility"; but, this 

 dropping backward was not an invariable movement. Some- 

 times the bee continued on into the shadow before dropping; 

 at other times it not only continued into the shadow, but it 

 rested there for some time; at yet other times it continued 

 on into the shadow without dropping at all. But this dropping 

 reaction does not prove that the movements of these bees are 

 tropisms in the narrow sense mentioned above. If the bee were 

 seeking to escape in the direction of the rays of light, on reaching 

 the shadow, the most natural response would be a return to 

 the light. 



CONCLUSIONS 



1. These parasitic bees used the mud cells out of which 

 they were hatched as homes, retiring to them at night. 



2. On leaving a quantity of honey from which it was feeding 

 for the first time, the bee always made a short flight of orienta- 

 tion. This indicates that they possess memory. 



3. Both males and females fed on the honey. 



4. The bees were so tame that, without any preliminary 

 training, they would rest on one's finger and eat honey there- 

 from. 



5. These bees mated in either the sunlight or shade; but 

 always on a \-ertical or horizontal support, never on the wing. 



6. These bees are endowed with a pronounced tendency 

 to move in the direction of the rays of light and towards their 

 source; but do not invariably so react, frequently they make 

 unpredictable responses. 



7. Light, heat, hunger, sexual restlessness and, perhaps, 

 other factors arouse in these bees an impulse to roam from 

 home. Coupled with this impulse to roam, there is an instinc- 

 tive tendency to seek freedom in the direction of the rays of 

 light. When following this instinctive tendency fails to bring 

 freedom, the bee tries other methods. In this endeavor many 

 bees make haphazard flights in all possible directions; while 

 others, in a more systematic manner, hover repeatedly before 



