284 
Journal of Agricultural Research 
Vol. XXIV, No 
35®, or brood-rearing temperature, the two corresponded. As the air 
temperature went up from 35° to 44® the temperature of the bee and 
that of the surrounding air were the same, as shown in Table II. 
When readings were taken at 52® and 58® C. the time factor entered, as 
the bees were at the point of their fatal temperature (about 46® to 48®). 
A bee was placed in the temperature box for 20 minutes before piercing. 
The thermocouple was placed in the thorax and kept there for seven 
minutes, readings being recorded every minute, during which time all 
movement ceased. Seven minutes later, when the couple was again 
inserted in the thorax, the body temperature of the bee was identical 
with that of the surrounding air. For the 100 bees used at 52® there 
was an average body temperature of 46®. If left at this temperature for 
30 minutes the bees died, which indicated that the fatal temperature 
was around 46® to 48®. 
About 250 bees were placed in a half pint (250-cc.) bottle. A ther¬ 
mocouple inserted near the top of the bottle gave a reading of 32® C. 
The temperature of the air in the room was at 25®. When the thermo¬ 
couple was inserted farther into the bottle, so that the bees clustered on 
the wires, the thermocouple registered 34®. Later, when the bees were 
quiet, the couple was reinserted and the temperature was at 29®. The 
bees were agitated and the temperature went up to 32®. Temperature 
readings were taken of individual bees, while the cluster was at 32®, and 
they gave an average temperature reading of 34®. 
Ten of these bees placed in a lo-cc. vial gave a temperature reading of 
32® C. When the bees were quiet, they had a temperature of 29®. 
Agitating the bees caused their temperature to rise slowly until it reached 
32® and remained there as long as the bees were active. This demon¬ 
strated that the bees can effect the temperature of their environment. 
If the heat radiated by the bee can be conserved, the temperature of 
the environment will go up. This in turn will permit the bee to raise 
its own temperature correspondingly, as there is a constant relationship 
between the body temperature of the bee and that of the environment 
it is in. 
As is shown by the temperature curve (fig. i) the supply of oxygen 
was a large factor in the amount of radiation that was set up by the bees. 
If the oxygen is limited, as may be done by corking the bees up tight in 
a bottle, the bees become inactive.and the temperature goes down. If, 
on the other hand, the cork is removed and fresh oxygen is admitted, 
the bees give an immediate response. 
TEMPERATURE OF ITALIAN DRONES 
A few temperature readings were made on the drones which were 
taken from the hive early in the morning before they had left the hive 
to fly. At room temperature, 23® C., the body temperature of the drones 
corresponded to that of the workers, while at 52® the drones, average 
temperature was 42.4® compared with 46® for the workers. 
TEMPERATURE OF CARNIOLIAN WORKERS 
In work on the Carniolians more emphasis was placed on the lower 
temperature than on the higher ones. In Table III we find that there 
is no difference between the Camiolian and Italian bees for the tempera¬ 
tures of 2.5®, 5.5®, and 9® C. A comparison of Tables II and III for the 
temperatures of 30®, 35®, and 52® gives the same results. 
