THE FLIGHT ACTIVITIES OP THE HONEYBEE 



29 



condition previously described, when the outgoing bees equal the 

 returning bees in number. Again, as flight closes, a considerable 

 shortening of the duration of the trips is shown. On May 15 (fig. 

 11), at 3.30 p. m., the two curves, representing the accumulated 

 totals of bees emerging and bees returning, come together, to di- 

 verge immediately to a resumption of the previous condition of 

 parallelism. This convergence with an immediate divergence was 

 occasioned by a threatening storm, illustrated in a previous curve 

 (fig. 4) , which sent all the bees in the field back to the hive and neces- 



Fig. 11 



-Oraph representing flight date for May 15, 1922, a day of good flow 

 of tuliptree honey 



sitated an abrupt shortening of the duration of the voyage. At the 

 end of the day the incoming curve, instead of ending below the out- 

 going curve, crosses it, the vertical distance between the ends of the 

 two curves representing the accumulated experimental error for this 

 day, when 467 more returns than exits were registered. This error 

 has naturally tended to reduce the distance between the two curves, 

 making the apparent duration of the voyages shorter than the real 

 duration. To obtain some idea of the magnitude of the error pro- 

 duced in the determination of the duration of the trips in the period 



