26 
as when a swarm is on the wing. When the curve for this day's 
record was plotted, an unusual peak, about 40 per cent higher than 
the normal trend of the curve, was noticeable at this time on both 
the ingoing and the outgoing curves. Although other peaks occur 
at different times, usually only on a single curve at one time, none was 
so marked as this particular one. If this peak was actually a re- 
sponse to this disturbance in the neighboring colom^, it is interest- 
ing to speculate as to the method of conveyance of the information 
to the bees within the experimental colony. This question suggests 
another use for these instruments, namely, a study of the reaction 
of bees to odor, sound, and other external stimuli. 
THE AVERAGE DURATION OF TRIPS 
A study of the factors which influence the length of time the bees 
are absent from the hive on each foraging trip is a distinct problem 
in itself. The amount of nectar available in the flowers, the position 
and nature of the nectaries, and the distance which the bees must 
travel to obtain this nectar are the chief factors which govern the 
average duration of the voyages; therefore, an intimate knowledge 
of this duration and its variations is of importance in a study of 
nectar secretion, especially with reference to the time of day when 
the maximum secretion occurs. At present it is possible to give 
only a limited selection of data from different parts of the season 
to show the daily and seasonal varia^ons in the duration of the 
trips which actually occurred in this experiment. 
A simple graphic representation of the average duration of the 
trips and their variations in the course of a day is obtained by 
plotting the progressive totals of all the bees which have left the 
hive and of all those that have returned up to the time of each suc- 
cessive reading from the cyclometers. The plotting of the exits 
gives a continually ascending curve to the end of the day's flight. 
The plotting of the returns gives a curve which follows the first 
curve in time, as determined by the average duration of each trip 
for that period of the day's flight. The horizontal distance between 
the two curves represents the average time the bees spend in the field. 
The vertical distance between the two curves at any time of the day 
represents the number of bees in the field at that time. 
If we suppose a. purely hypothetical case, in which a constant 
number of bees leave the hive and return within a certain definite 
interval of time, throughout the day, two parallel straight lines, 
representing the exits and returns, would be obtained when plotted 
as described above. By comparing two similar triangles on such a 
diagram it is found that the ratio of the number of bees (n) which 
return in a given interval of time (t), is to this time (t) as the 
number of bees in the field (/) is to the average duration of the 
trip (x) ; that is, n:t:: fix, or x= — • Turning now, for example, 
lb 
to Table 3 (May 15, fig. 4) and Table 4 (July 10, fig. 9) it is found 
that the number of bees in the field increases at the beginning of 
the day and diminishes as the day closes. Between these two periods 
of the day there is a period during which the total number of bees 
in the field at any particular time is reasonably near a constant num- 
