MR. NEWPORT ON THE TEMPERATURE OF INSECTS. 
277 
able to infer that the subsequent arousing of the insect from this hybernating condi- 
tion arises, in addition to the stimulus of increased temperature in the surrounding 
medium, partly also from the stimulus of a more perfect aeration of its fluids, through 
means of the greater quantity of air which necessarily enters its enlarging respiratory 
organs. These opinions are supported by the facts that some insects pass into the 
pupa state at two different periods of the year, and that their subsequent development 
into the perfect state depends upon the period at which they enter into the pupa. 
Thus the common Cabbage Butterflies, Papilio brassicce, Linn., and P. Napi, Linn., 
when changed from larvae to pupae in the middle of summer, become perfect insects 
within a fortnight ; but when the change into the pupa state takes place at the end 
of summer, the perfect insects are not developed until the following spring, unless, 
as shown long ago by Reaumur, they are placed in a warm atmosphere, when they 
may at any time be developed within a few days, even in the months of December 
and January. Besides these facts, and a variety of others which are equally well 
known, every one is aware that the hybernation of many insects occurs at compara- 
tively high degrees of temperature. The facts connected with the presumed plethoric 
condition of insects before hybernating are equally referable to those perfect insects 
which pass the winter months in hybernacula as to larvse which are about to pass 
into the pupa state, since it is found that they always have a much larger accumula- 
tion of fat in the autumn than at other seasons of the year. This is the case in the 
bodies of Vanessa Atalanta, Steph., V. Io } Steph., V. urticce , and in the Cabbage But- 
terflies just noticed ; and it is well known to the cottager that when the flowers have 
not yielded an abundance of honey in the latter part of the summer, the bees in his 
hives will have less chance of existing through the winter than when the production of 
honey has been plentiful. This latter circumstance may, perhaps, be said to arise 
from a deficiency in the quantity of honey stored up by the bees, but I have strong 
reasons for believing that it arises chiefly from the bees being in a worse bodily con- 
dition, and having but a small quantity of nutriment stored up within their own 
systems, which alone enables them to pass some portion of the winter in a state of 
repose. If the female of the common Humble Bee, Bombus terrestris, Steph., which 
sleeps through the winter andAppears early in the following spring, be examined about 
the end of September, its abdomen is found to be supplied with large bags of fat. At 
that period the insect is less active, and evolves a smaller quantity of heat than in 
the spring when there is a much lower temperature of the atmosphere. And if at 
that period the insect be deprived of food it will continue to live, very much longer 
than it would have lived, under similar circumstances, and exactly at the same tem- 
perature of the atmosphere in the month of April. About the end of September I 
confined two large females, Bombus terrestris and B. lapidarius , Steph., in the same 
box without food, and placed them in my sitting room, the temperature of which was 
seldom lower than 60° Fahr. and often 65°, during the whole time of their confine- 
ment. When first confined they were both very active. B. terrestris died on the 
27th of October, and B. lapidarius on the 5th of November, having each of them been 
confined about a month or five weeks. Now the very same species when confined in 
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