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XVII. On the Temperature of Insects, and its connexion with the Functions of Respi- 
ration and Circulation in this Class of Invertebrated Animals. By George 
Newport, Esq., Member of the Royal College of Surgeons, and of the Entomo- 
logical Society of London. Communicated by P. M. Roget, M.D. Sec. R.S. 
Received June 5, — Read June 15, 1837. 
Every naturalist is aware that many species of insects, particularly of hymeno- 
pterous insects, which live in society, maintain a degree of heat in their dwellings con- 
siderably above that of the external atmosphere, but no one, I believe, has hitherto 
demonstrated the interesting facts that every individual insect when in a state of 
activity maintains a separate temperature of body considerably above that of the sur- 
rounding atmosphere, or medium in which it is living, and that the amount of tempe- 
rature varies in different species of insects, and in the different states of those species. 
Previously, therefore, to considering the connection which subsists between the evo- 
lution of animal heat and the functions of respiration and circulation in insects, I 
shall endeavour to prove that every species maintains a distinct temperature of body, 
the amount of which differs in the different states of the insect. 
I was first led to the particular consideration of the subject of temperature in in- 
sects by some observations on the temperature of wild bees in their natural haunts, 
which were made by myself at Richborough, near Sandwich in Kent, in the autumn 
of 1832, at the suggestion of Dr. Marshall PIall, for the purpose, — similar to that 
of my observations on respiration, as noticed on a former occasion*, — of ascertaining 
what relation, if any, subsists between the natural heat of these insects in their hyber- 
nating condition and the irritability of their muscular fibre. The results of these 
observations on the temperature of Bees are shown on Table III., Nos. 1 to 14, 
and together with many other facts connected with the physiology of insects were 
communicated to Dr. Hall a short time afterwards ■f-. These observations were 
* Philosophical Transactions, Part II. 1836, p. 551. 
t In submitting these observations on the Temperature of Insects to the consideration of the Royal Society, 
I have felt myself imperatively called upon to make the above remark, in explanation of the nature of my sup- 
posed obligations to Dr. Marshall Hall, -with regard to this and other subjects connected with the Physio- 
logy of Insects, in consequence of certain misrepresentations which were made on a recent occasion respecting 
my communications with that gentleman ; and I beg further to state, that many of the views here advanced 
respecting the temperature of insects, and also most of the subjoined Tables, particularly those on the tempera- 
ture of the Hive Bee, from the commencement of my observations to the month of May 1836, were commu- 
nicated by myself to Dr. Marshall Hall, at his own particular request, in the beginning of July 1S36, in the 
presence of my intelligent friend, and late pupil, Mr. John Osborn, who assisted me in making the observa- 
tions, and unto whom I am indebted for much valuable assistance during my investigations. 
MDCCCXXXVII. 2 M 
