324 
MR. NEWPORT ON THE TEMPERATURE OF INSECTS. 
proof this, both that the pupa was transpiring through the pupa case, and also that 
the transpired matter contained carbonic acid. 
Conclusion . 
The very great length unto which this paper has already been extended, neces- 
sarily prevents me from entering so fully into all the circumstances connected with 
the evolution of heat in insects as the great importance attached to this interesting 
subject demands ; I shall, therefore, review the contents of this paper, and other cir- 
cumstances connected with the production of animal heat, with as much conciseness 
as possible. 
On comparing the whole of the facts we have just examined, we cannot fail to ob- 
serve the very close relation which subsists between the amount of heat developed, 
and the quantity of respiration. We have seen in the larva, the pupa, and the 
perfect insect, -that when the respiration is accelerated the temperature is also in- 
creased, and that when respiration is diminished the temperature subsides. When 
the insect is sleeping, its respiration gradually becomes slower, and its temperature 
continues to lessen until the insect is aroused, when immediately after the first respi- 
rations it is again increased. When the insect falls into a state of hybernation, and 
its respiration is suspended, its evolution of heat becomes so likewise. When the 
insect is most active, and respiring most voluminously, its amount of temperature 
is at its maximum, and is very great, and corresponds with the quantity of respira- 
tion, and, as in the Bee, an immense quantity of heat passes off into the surrounding 
medium. When the insect wishes to impart heat to its young it can do so at plea- 
sure, and can voluntarily increase its own temperature. It does this by accelera- 
ting its respiration. At those times, as shown in the comparative observations, the 
insect evolves in one hour, in this state of activity and excitement, at least twenty 
times the amount of heat, and consumes nearly twenty times the quantity of air, 
which it consumes at the same temperature when in a state of repose. In insects 
which live in society the temperature of their dwellings is increased in proportion to 
the activity of the inmates, and consequent amount of their respiration. In the hive 
it is steadily increased until the time of swarming. In the winter when the bees are 
quiet, and their respiration is exceedingly low, and when not a bee is observed venti- 
lating at the entrance, the temperature of the hive may be raised in a few minutes, 
very many degrees, by disturbing the inmates, and thereby increasing their respira- 
tion, until such an amount of heat is evolved, and so much air is deteriorated, as to 
become oppressive and noxious to the bees, many of whom, although the open atmo- 
sphere be too cold for them to venture abroad, will come to the entrance of the hive 
and begin as laboriously to ventilate the interior, by vibrating their wings, as in the 
midst of summer. The quantity of free heat is always greatest in the hive when the 
bees are most active, and least when they are most quiet. With regard to the habits 
and anatomical structure of insects, the amount of heat is by far greatest in volant 
