MR. NEWPORT ON THE TEMPERATURE OF INSECTS. 
327 
sidered, and connected with that very remarkable one, the voluntary power of pro- 
ducing heat possessed by the Bee, must lead us to conclude, that although, doubt- 
less, the whole of the functions of the body are more or less remotely concerned in 
the production of heat, yet that the immediate source of its evolution seems to be 
chemical changes effected during respiration, and that the nervous system is only 
secondarily concerned. 
Appendix, 
Since the preceding paper on the Temperature of Insects was submitted to the Royal Society, circumstances 
have enabled me to ascertain a few additional facts respecting the temperature of some other species which I 
had not heretofore any opportunity of examining, and these the Council have kindly permitted me to subjoin 
to my paper. 
I am not aware that the temperature of the nest of the common wasp has ever before been examined, and it 
is therefore pleasing to find that all the circumstances connected with the evolution of heat in the nest of this 
species are in perfect accordance with the observations made on the neighbouring families of hive and hum- 
ble bees. 
On the 11th of August, during the past summer (1837), I dug away the soil from the top of a nest of Vespa 
vulgaris which was situated in a bank of earth at the depth of about seven inches from the surface. The nest 
was nine inches in diameter, so that the colony was by no means a small one. The temperature of the atmo- 
sphere, when the covering of the nest was removed, at 4| p.m. was 70° Fahr. When the thermometer was 
passed through the top of the nest the mercury rose immediately to 80°. In about ten or fifteen minutes 
afterwards, when the colony had become disturbed, and the thermometer was passed a little deeper into the 
nest, the mercury rose to 95°. This distinctly proves that the evolution of heat in the wasps’ nest is greatly 
increased, as in the beehive, when the insects have become excited. At p.m. the temperature of the atmo- 
sphere was 65° Fahr., and the wasps having now become more quiet, the temperature of the nest, which had 
remained with its upper surface exposed since the last observation, was only 90° Fahr. ; but an hour afterwards, 
when the temperature of the atmosphere had sunk to 63°, that of the nest had risen to 91°, the thermometer 
having remained undisturbed in the nest since the last observation. This increase of temperature was readily 
explained by a great number of the excited insects, which had been flying around the spot, having now returned 
to the nest. Thus the circumstances connected with the evolution of heat in the nests of the predaceous and 
in the melliferous Hymenoptera are precisely similar ; and they are similar also in another interesting family of 
this order — the ants. It is elsewhere noticed* that Juch found the temperature of an ant-hill about 15° Fahr. 
above that of the atmosphere. My own observations are in accordance with this statement. On the 27th of 
July 1837 I examined the temperature of the nest of Formica herculanea, Linn. The temperature of the atmo- 
sphere in the shade, at 1 1 a.m., was 7 6° Fahr., but when the thermoipeter was exposed on the ground to the full 
rays of the sun the mercury rose to 95° Fahr. The nest was rather a small one, and at the time of commencing 
the observations was completely undisturbed. When the thermometer was first passed into it, to the depth of 
five inches, the temperature was maintained steadily at 84° Fahr. ; but within six or eight minutes afterwards, 
when the insects had become excited by the presence of the thermometer, and were running about in every 
direction in a state of the greatest agitation, the temperature of the nest rose to 93° Fahr., and in a few minutes 
after this, when the insects were still more excited, to 95°’5, and a little nearer the surface, where the commo- 
tion was greatest, to 98°'6Fahr. During these observations the ant-hill was carefully shaded from the rays 
of the sun, in order to avoid all source of error. When the ant-hill was again exposed to the sun, and the 
thermometer placed upon its surface, the mercury rose to 108° Fahr. This was a temperature much too great 
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