360 DWIGHT E. MINNICH 



sible. Two kinds of blackening material were used, viz., kmp- 

 black in shellac and a dead black paint known commercially 

 as 'Jap-a-lac' The latter proved the more satisfactory and was 

 used throughout the majority of experiments. 



Although bees under ether often began to recover in five to 

 ten minutes, they were not removed from the pinning board for 

 twenty to twenty-five minutes, when the covering of the eye was 

 well hardened. Recovery from anaesthesia was usually com- 

 plete in an hour and often much less. As a rule, however, opera- 

 tions were carried out in the evening, and the bees were not sub- 

 jected to further experiment until the following day. Ample 

 time was thus allowed for the animals to recover as much as 

 possible from the effects of the operation. 



V. BEHAVIOR OF NORMAL BEES 

 1 . Kinetic effect of light 



The remarkable sensitivity of the honey-bee to photic stimu- 

 lation must have long been patent to students of its behavior. 

 Bethe ('98, p. 83) says, "Das Licht ist bei diesen Tagthieren 

 [bees, flies, etc.] der auslosende Reiz zum Fliegen; in einer dunklen 

 Schachtel fliegt keine Biene auf , auch nicht, wenn man sie reizt. 

 Das Licht gibt die ReguUrung beim Fluge ab." This observa- 

 tion was repeatedly confirmed in the present experiments. When 

 collecting bees from flowers, fifteen to twenty individuals were 

 confined in a siagle cage, which was then placed in a closed box. 

 Although at the height of activity when captured, a few minutes 

 in the darkness of the box seldom failed to reduce these animals 

 to a state of quiescence. If a little light was admitted to the box, 

 however, by even partially removing the hd, there was a sudden 

 resxunption of activity. 



Precisely the same behavior was exhibited by wingless bees. 

 If confined in a dark box, they were, as a rule, reduced to com- 

 parative inactivity. A brief exposure to light, however, was 

 usually sufficient to excite vigorous locomotion, and continued 

 exposure not infrequently resulted in the maintenance of an 

 intense activity for extended intervals of time. 



