326 
MR. NEWPORT ON THE TEMPERATURE OF INSECTS. 
after the first respirations*, when the heat is becoming apparent. With regard to 
the digestive process, we have seen that when the animal is taking food it has the 
greatest amount of gaseous expenditure from its body, and that the greatest amount 
of heat, when in a state of quietude, is then generated. But a, greater quantity of air 
is then consumed, in assimilating the new matter which has been taken into the sy- 
stem, and the quantity of heat is still further increased if the animal becomes active, 
and this is regulated by the increased expenditure from the surface of the body. 
Lastly, we have seen that in the more perfect volant insects, the Bees, Sphinges, &c., 
there is the largest amount of heat produced, and the greatest quantity of air con- 
sumed, but the nervous system is also largely developed, and hence it may fairly be 
supposed to have much influence in the development of heat. But on the other hand 
we find many insects, as the Meloe and its congeners, which produce a large amount 
of heat, in which the nervous system is comparatively small, while these insects have 
large respiratory organs, and a large amount of respiration. In the Staphylimis the 
nervous system is exceedingly large, compared with the size of the body, but the re- 
spiratory organs are by no means small, while the amount of heat is very moderate. 
In the Carabus the nervous system is also large, as are likewise the organs of respi- 
ration, but the amount of heat and activity of respiration are low, and the same is the 
case in the Blaps, in which the nervous system is rather small. If the development 
of heat depends upon the nervous system, or the number of ganglia, the Leech, which 
has twenty-two ganglia, ought to generate more heat than the larvae of lepidopterous 
insects, which have but ten or twelve, and the larva ought to generate as much as the 
perfect insect. In the larvae of the Bee, the Hornet, Ichneumon, and Tenthredo, 
which generate so large an amount of heat, the nervous system is exceedingly small ; 
and if, as some suppose, heat is the result of muscular contraction, surely it ought 
to be most developed where there is the greatest amount of muscular contractility; 
it ought to be generated more in the Leech than in other articulated animals, and 
in those Vertebrata which are peculiarly noted as cold-blooded. These facts con- 
* This is in perfect accordance with the condition of the circulation in the human body during sleep, and 
at the moment of waking, as noticed by Blumenbach, and as I myself once had an opportunity of observing in 
a female patient who was suffering from severe fracture of the skull, for which she had been trephined ; subse- 
quently to which, a large portion of the bone (the right parietal) became affected with necrosis and was removed 
by operation, and the patient afterwards gradually recovered. At least one-third of the whole parietal bone had 
been removed, and a large surface of the dura mater being thus exposed, the activity of the circulation in the 
brain was readily observed. I thought this a fair opportunity, as the patient was recovering, for observing the 
state of the circulation during sleep, and at the moment of waking. The patient was sleeping soundly at the 
time of the observation, and while she remained entirely undisturbed, the pulsations in the arteries of the dura 
mater were at the rate of ninety-four beats per minute, and were perfectly synchronous with the pulsations at 
the wrists ; but immediately she began to inspire deeply at the moment of waking, the pulsations became much 
accelerated. At the instant of waking, the patient fetched a full and deep inspiration, and in less than a minute 
and a half after this, the patient being perfectly awake, the pulsations amounted to 104 beats per minute, thus 
making a difference of about 600 beats per hour in the rate of pulsation when sleeping and immediately after 
waking. 
