55X 



THE QUARTERLY REVIEW OF BIOLOGY 



a physiological injury, for the animals 

 died after twenty-four hours in water at 



34°- 



The insects used in the experiments to 

 show the effect of low temperature on 

 C0 2 output were somewhat larger than 

 those used in the previous experiments. 

 The former experiments were carried on in 

 the fall months, while the present experi- 

 ments were carried on in the winter, since 

 it was thought advisable to use running 

 water from the lake at a time when it 

 maintained a constant temperature of 6°. 

 Comparisons may be made, however, with 

 insects of similar weight in the controls, 

 to determine the relative amounts of 

 carbon dioxide given off. The same 

 scheme of duration of time at each tem- 

 perature was used as previously employed 

 in the records with rising temperature. 

 Figure 4 shows that the carbon dioxide 

 output decreased progressively with fall- 



ing temperature after twenty-four hour 

 durations, but also shows an acclimatiza- 

 tion to a low temperature after being ex- 

 posed to it for a longer period of time. 

 The carbon dioxide output drops for each 

 drop in temperature, but the output in- 

 creases again in forty-eight and seventy- 

 two hours at a given temperature. At 

 3 , the metabolic processes are going on 

 at a very slow rate and acclimatization at 

 this temperature was only slight. Low 

 temperature did not affect the nymphs in 

 any permanent way, for they lived a 

 normal length of time after the experi-i 

 ment was completed. 



The writer has attempted to review the, 

 field of metabolic experiments on insects • 

 and to point out the interesting work 

 that has been done on this group of 

 animals. There are many phases of the- 

 subject yet untouched and these offer 

 tempting problems for further research.; 



LIST OF LITERATURE 



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Jour. Exp. Zool., z6: 4x3-458. 

 (2.) Battelli, F., und Stern, L. 1913. Intensitat 



des respiratorischen Gaswechsels der Insekten. 



Biochem. Zeitschr., 56: 50-58. 



(3) Bodine, J. H. 1911. Factors influencing the 



water content and the rate of metabolism of 

 certain Orthoptera. Jour. Exp. Zool., yx.: 

 137-164. 



(4) • 192-3- Hibernation in Orthoptera. 



Jour. Exp. Zool., 37: 457-488. 



(5) Bodine, J. H., and.ORR, R. R. 1915. Respira- 



tory metabolism. Biol. Bull., 48: 1-14. 



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The Quart. Rev. Biol., z: 181-^03. 



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der Stoffwechsels, insbesondere der Respira- 

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phology. New York. Vol. 1. 



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les changements de temperature et la con- 

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froid. Archives Neerland. de Physiologie, 7:; 

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(10) Farkas, K. 1903. Uber den Energieumsatzi 



des Seidenspinners wahrend der Entwicklungi 

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 Pfluger's Arch. f. d. ges. Physiol., 98: 490-1 

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(11) Fink, D. E. 19Z5. Metabolism during em-i 



bryonic and metamorphic development of: 

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(iz) . 19Z5. Physiological studies on hiber-i 



nation in the potato beetle. Biol. Bull., 49:; 

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(13) Krogh, A. 1914. On the rate of development: 



and carbon dioxide production of chrysalids I 

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 Zeitschr. f. allg. Physiol., 16: 178-190. 



(14) — -. 1916. The Respiratory Exchange of: 



Animals and Man. London and New York. ; 



(15) Loeb, J. 1888. Der Einfluss des Lichtes auf . 



die Oxidationsvorgange in thierischen Organ- 

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influence of food and temperature upon the 



