34 BULLETIN 1349, IT. S. DEPARTMENT OE AGRICULTURE 
presence of bees too young for field work does not in itself induce 
swarming unless there is such an excess of young bees beyond those 
required for hive duties as to interfere with the routine of the colonv. 
Any appreciable excess of young bees arises, not for the sake of 
intensifying the natural swarming impulse, but rather as a result of 
other factors. Such an excess is bound to occur if conditions within 
the colony prevent a large number of young bees from performing 
the functions of their normal life cycle. This would be the case 
whenever brood-rearing activity reached the limit of cells available 
at a period when the brood-rearing area would have been further 
enlarged if more cells had been at hand, or if under similar conditions 
brood rearing were restricted through a reduction in the number of 
cells available for brood by their use for incoming nectar or pollen. 
The egg-laying rate being then reduced to a noticeable extent for 
several days, there would eventually be fewer larvae to care for, fewer 
cells to clean out, fewer cells to be sealed over, and a diminution in 
all of the activities incident to a period of intense brood rearing. In 
consequence, since such duties are usually performed by young bees, 
there would be many of the latter out of a job, so to speak. 
Throughout the observations in this research it has been noted 
that all colonies, strong as well as weak, tend to crowd incoming- 
nectar not only around the border of the brood nest but even within 
the brood area itself whenever an empty cell is found. Such a ten- 
dency has long been recognized. Consequently, if during a honey 
flow many cells within the brood area proper become available for 
depositing incoming nectar through the emergence of large numbers 
of young bees, the queen may be restricted suddenly in her activity, 
as happened in 1921 to the queen in colony Xo. 4. Under these 
conditions there would result an excess of youno- bees. Whether 
this excess would be large enough to induce swarming would depend 
on the degree and duration of restriction of the queen's activities. 
In the case of colony Xo. 4 and the others the restriction was never 
of long duration. It has often been observed that just prior to 
swarming the queen almost entirely ceases egg la}ung, so that all 
unsealed brood disappears. Such a condition is simply the natural 
result if any large number of brood cells have been used for another 
purpose. Not only may the number of cells available for egg laying 
become insufficient through diversion to use for incoming nectar 
and pollen, but even without any reduction in number by these 
causes there will be too few whenever brood rearing itself reaches the 
limit of cells available in the hive. During a period of normal 
seasonal increase in brood-rearing activity, idle field bees may at 
times cause a congestion within the hive which apparently inter- 
feres with brood rearing. Any of these conditions may arise 
independently of any honey flow, and would tend to explain the fact 
that swarming is not always correlated with a honey flow. 
In the colonies under discussion a swarming impulse was doubtless 
restrained by the fact that at no time was any colony crowded for 
room long enough to cause a serious break in the continuity of brood 
rearing at a time when the tendency toward brood-rearing activity 
was strong. Whenever any queen became restricted in any particular 
hive body during a period favorable to continued, heightened brood- 
rearing activity, she was able to migrate to a more suitable region 
within the hive. Through this ability to transfer her activity else- 
