MR. NEWPORT ON THE TEMPERATURE OF INSECTS. 
301 
amount of heat developed in a given time was in proportion to the quantity and ac- 
tivity of respiration, and that the temperature of each species of insect can only be 
increased to a certain extent above the temperature of the medium in which it is 
living, and that when it has arrived at that point, whatever it happens to be, a copious 
cutaneous transpiration takes place ; and if the temperature be still increased, the 
body of the insect becomes bathed in perspiration, and its temperature is immedi- 
ately begun to be reduced. Now the degree unto which the temperature of insects 
may be increased above that of the medium in which they are living, varies in the 
different species as well as in the different genera of insects ; each species has a cer- 
tain standard of its own, beyond which its increase of temperature cannot be carried. 
In some insects, as in the Hive Bee, this may perhaps amount to from fifteen to 
twenty degrees, while in others it perhaps scarcely exceeds one or two degrees above 
the temperature of the surrounding medium. Besides this, it has been found that 
insects have a power of generating heat when confined in a given space, and that this 
power is in proportion to the activity of respiration. I have had numerous proofs of 
this fact in my observations on the varying temperature of the hive. 
My experiments on the hive were conducted in the following manner: a common 
straw hive was placed with its entrance hole in the direction of another wooden hive, 
which was standing beside it in a bee-house, which was so constructed that the whole 
of the back part of the house could be removed or closed at pleasure. The proper 
entrance for the bees at the front of the bee-house was directly into the wooden hive, 
from the side of which there was a little covered communication with the entrance 
hole of the straw hive, to serve as a passage for the bees and a connection between 
the wooden and straw hive. The object of this was to prevent any sudden effect 
upon the temperature of the hive by changes which might occur in the temperature 
of the air without. The interior of the straw hive was thus subjected as little as pos- 
sible to the variations in the open atmosphere, since the bees were obliged to pass 
through the empty wooden hive to its entrance hole before they could reach the open 
air. In order to make the experiment with the greatest accuracy, it was necessary 
that the bees should never be disturbed while making an observation, and therefore 
a small crow-quill sized thermometer, with a long free bulb, was passed through a 
hole just large enough to admit it in the top of the straw hive, about eight inches 
from the centre, and retained there during the whole of my subsequent observations 
without being removed or touched. The bees at first seemed a little inconvenienced 
by its presence, but within two or three days they became accustomed to it, and, as I 
had reason to believe, removed the comb and wax from around it, so that the bulb of 
the instrument was remaining about an inch within the free space of the hive, and 
the observations were then made at intervals, and with the greatest accuracy. The 
temperature of the atmosphere was taken with a thermometer of similar size and con- 
struction to the one used for the hive, and the two had been carefully compared be- 
fore the first was passed into the hive. It was thus only necessary to notice from 
2 r 2 
