i a 
1914} Longevity of Insects 351 
enlargement in nuclear material is the ideal condition for dis- 
integration. This has been shown to be the case in the liver 
cells of the hedgehog by Carlier. 
In my experiments, I have found that the tissues of hibernat- 
ing Codling moth larve show the presence of granular sub- 
stances, immediately after the larve have been exposed to the 
low temperature. Probably these granules indicate cytoplasmic 
obstructions which due to the disintegration and inactivity 
of cells have been thus disposed of, leaving the cell in a rejuve- 
nated condition. Tower found in the potato beetle these same 
granules present in hibernation and immediately after hiber- 
nation, a resumption of the activities of the cell, a loss of the 
vegetative unstaining quality and a more watery and less 
differentiated appearing condition of the cell. If the insects 
that are hibernating are exposed for increasing lengths of time 
to a low temperature and then placed at a high temperature, 
the tissues will have become rejuvenated and therefore with an 
increase in temperature, acceleration of the metabolic processes 
and of growth can take place. 
However, if this exposure to cold is of too long a duration, 
either too much of the water content will have been lost and 
coagulation corresponding with permanent heat rigor, will set 
in at a lower temperature than after but a short exposure to 
cold or disintegration of tissues will have gone on to too great 
an extent. 
BIBLIOGRAPHY. 
1. Abbe, C. First Report on the Relation between Climate and Crops. Bull. 
36.U. S. W. B. ’05. 
2. Alsberg, C. L. Mechanism of Cell Activity. Science, vol. 34, page 97. 
3. Bachmetjew, P. Temperature Verhaeltnisse bei Insekten. Sophia ’01. 
4. ————. Experimental Entom. Studien vom physik.-chem Standpunkt 
aus II Band. Sophia, 1907. 
5. Baker, F. C. The Lymnaeidae of North and Middle America. Chicago 
er Se., Sp. Pub. No. 3, 1911. 
6. Bellion, M. Rech. exp. sur l’hibernation de l’escargot. Ann. Univ. Lyon, 
ser 27, 1909. 
( Boring, A. M. Effects of Different Temperatures on the Size of Nuclei. Arch. 
Ent.-mech Org., vol. 28, page 118. 
8. Calkins, G. M. The Life Cycle of Paramoecium caudatum. Arch. Ent.- 
mech. Org., vol. 15, page 139. 
9. Carlier, E. W. Contribution to the Histology of the Hedgehog. Jr. Anat. 
and Physiol., vol. 27, page 85. 
10. Child, C.-M... The study of Senescence and Rejuvenescence. Arch Ent.- 
mech Org., Vol. 31, page 537. 
Lh Physol. Isolation of Parts and Fission in Planaria. Arch. 
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