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MR. NEWPORT ON THE TEMPERATURE OF INSECTS. 
These facts are sufficient to prove that insects have a high temperature of body, 
and that it is higher in their perfect than in their larva or infant condition. They 
also beautifully accord with the facts ascertained, and the views deduced from them 
by Dr. Edwards, respecting the difference between the temperature of the young 
mammiferous animals and their perfect adults. 
II. Temperature of Insects as influenced by various conditions. 
Abstinence, Inactivity, Sleep, Hybernation and inordinate Excitement . 
1. Abstinence . 
Having shown the difference between the temperature of the larva and perfect in- 
sect in a state of activity, we come next to the consideration of certain conditions 
under which the temperature both of the perfect insect and of the larva will some- 
times subside, almost to that of the surrounding medium. When an insect, whether 
it be in its earlier or later condition, has been long deprived of food, its power of ge- 
nerating and of maintaining its natural heat is diminished. But this diminution of 
power does not keep pace with the length of time it has been fasting, but is only in 
an inverse degree. In the larva of Sphinx ligustri, Table XII., and in Acrida viri- 
dissima, Table VI. Nos. 9 to 16, the amount of heat is much below the usual quantity 
evolved when the insect is not deprived of food, and in a state of activity. When 
the proper quantity of food is again supplied to these insects, their respiration is re- 
stored to its original condition, and they again evolve a full amount of heat. When 
a larva that has been deprived of food, or has been fed sparingly, is preparing for 
transformation, its natural temperature is reduced to within two or three tenths of a 
degree of that of the surrounding medium. This was the case with the larva of 
Cerura vinula, Steph. (Table X. No. 30, B.), which although actively employed 
spinning its cocoon, had, at one time, a temperature of only two tenths of a degree 
above that of the atmosphere; while the other specimen. No. 1 . A, which had been sup- 
plied with its full amount of food of proper quality, had a temperature under similar 
circumstances, and almost at the same hour, of *7 tenths above that of the atmosphere. 
In another larva of Sphinx ligustri, which having been inadequately supplied with 
food soon after it had assumed its last skin, and thereby retarded three or four days 
beyond the usual period before it began to prepare for transformation, the tempera- 
ture of its body, while in the state of the greatest muscular excitement in attempting 
to rupture and cast off its exuviae, was only ‘3 tenths of a degree above that of the 
atmosphere. 
2. Inactivity . 
Another source of diminished temperature in insects is inactivity. In this condi- 
tion, as in a state of abstinence, the quantity of respiration is also diminished. When 
an insect becomes quiet, after having continued for some time in a state of moderate 
