316 
MR. NEWPORT ON THE TEMPERATURE OF INSECTS. 
Thus also in the larva of the Puss Moth, Table X. A. No. 7 to 27. Although the 
temperature of the atmosphere was gradually raised through twelve successive hours 
from 69 0, 5 Fahr. at 5f a.m., — when the larva, which had been sleeping through 
several hours, and had a temperature of only 0, 5 above that of the atmosphere, and 
its pulse was beating at the rate of forty-seven per minute, — to 80 o, 4 Fahr. at p.m. 
the insect then had a temperature of only ° - 8, while its pulse was beating at the rate 
of eighty-eight per minute. Again, at 7 on the following morning, atmosphere 7o°‘ 2 
Fahr., the temperature of the insect at rest was only°9 ; at the expiration of one hour 
and a half it had not been increased, and the insect was still at rest, but the pulse 
had risen to sixty-eight, while at 9 a.m., when the insect was aroused and feeding, its 
amount of temperature was still the same, but the number of its pulsations then 
amounted to seventy-two. At 7 o’clock on the following morning, when the insect 
was active and preparing for transformation, its temperature being °‘7, its pulsations 
were at the rate of sixty per minute ; but half an hour afterwards, when the tempe- 
rature of the insect was 0, 9, the number of pulsations was not increased ; and at the 
expiration of an hour, when the temperature had again sunk to °‘7, the pulse had also 
subsided to fifty-four. This very insect, A. No. 1, which immediately after it was cap- 
tured had been placed in a box in my coat-pocket, and after remaining there for some 
time, excited by immoderate warmth, had a temperature of 13 0, 5 Fahr. above that of 
the atmosphere, which was then 68° Fahr., while the pulse of the insect was ninety- 
nine per minute. But one hour afterwards, when its temperature had sunk to 2 0, 3, 
the pulsations were only sixty-four. At the expiration of another quarter of an hour 
they had risen again to seventy-two, while the temperature of the insect had sunk to 
1 0, 6 Fahr. Thus then, although in general we cannot fail to observe the almost con- 
stant uniformity or correspondence between the number of pulsations and the tempe- 
rature of the insect, as in Nos. 6, 14 and 17, it is evident that the amount of tempe- 
rature does not necessarily depend upon the rate or mere velocity of pulsation. 
On examining the Table now referred to it will be seen that there is a remarkable 
difference in the rate of pulsation, as well as in the temperature of the larva of the 
Puss Moth and of the Sphinx ligustri of the same age, and at about the same tempe- 
rature of the atmosphere as on Tables VIII. and X., from which it is seen that neither 
the temperature of body nor the rate of pulsation is so great in the Sphinx as in the 
Puss Moth, while in both is observed the general coincidence of the rate of pulsation 
with the amount of temperature. In both the Tables VIII. and IX. it is seen that 
when the larva is about to change into the pupa state the pulsations are reduced from 
thirty-two to twenty-eight, and even to twenty-six ; and when the change into the 
pupa state is completed, the rate of pulsation is not more, in some instances, than 
twelve beats per minute. When the insect is in its most complete state of hyberna- 
tion the circulation in the pupa is reduced to its lowest condition, and there is perhaps 
an almost entire absence of pulsation, although I have reason to believe that the fluids 
still circulate even when there is no development of external heat. 
