The Life of the Individual 
107 
Since it may not at first glance be clear how the age at 
which bees perform certain functions is determined, it may 
be well to explain the simple method by which this is accom¬ 
plished. If the queen is removed from a colony of black 
(German) bees and a yellow (Italian) queen is at once in¬ 
troduced, for a period of twenty-one days after the removal 
of the old queen the young worker bees which emerge from 
the cells are black, since they are the progeny of the old 
queen. At the end of that time, however, the worker brood 
from the black queen has all emerged and yellow bees begin 
to appear. The time at which the yellow bees first perform 
certain functions may now be determined. This experi¬ 
ment may be variously modified, as by the removal of all 
the brood of the black queen at once or by the placing of 
a frame of brood from an Italian colony in a colony of black 
bees. The introduction of Italian bees into Germany and 
later into America has been an important factor in enabling 
investigators to learn many of the phenomena of the hive, 
for the use of bees of two colors 1 is often of the highest 
importance. 
The labor mthin the hive. 
When the workers first emerge from the cells they take 
no part in the work of the hive for a day or two, nor do they 
leave the hive. The first flight in front of the hive is usually 
when they are about a week old, if the weather is favorable, 
and these flights are continued on warm bright days until 
they are nearly three weeks old. Although they do not go 
far at first they may remain on the wing for a considerable 
period. That these early flights are necessary in enabling 
the young bees to void their feces is indicated by the fact 
that if confined they become restless. 2 The abdomens of 
young bees are frequently distended with feces. 
1 Another method of marking bees for observation is mentioned by Cas¬ 
teel, Cir. No. 161, Bureau of Entomology, p. 5. The method employed 
was to paint bees with different colors and also to number them. 
2 This was observed when colonies containing young bees were placed 
