876 



SCIENCE 



[N. S. Vol. XLI. No. 1067 



ture was between the two incubator tempera- 

 tures. 



The following table gives the average length 

 of period of each stage: 



TABLE II 



Average Duration of Each Stage — Mosquitoes 



SNYDER'S RESULTS ON THE RELATION OP TEMPERA- 

 TURE TO THE RATE OP HEART BEAT 



TABLE OP RESULTS OP WORK WITH MOSQUITOES 



DISCUSSION 



A study of Tables I. and II. brings to mind 

 the interesting results of Snyder on the rate 

 of heart beat of the tortoise heart. He found 

 that between temperatures 5° and 30° C, the 

 number of heart beats is doubled to trebled for 

 every rise of 10° C. temperature. 



These results agree with the work of Clausen 

 (reference 2, below) on the amount of CO5 

 produced by 100 gr. seeds of lupines in one 

 hour at different temperatures. 



CLAUSEN'S RESULTS ON THE RELATION OP TEMPERA- 

 TURE TO THE AMOUNT OP COj PRODUCED 

 Temperature C0» Produced 



0° 7.27 



5° 13.86 



10° 18.11 



15° 34.87 



20° 43.55 



25° 58.76 



30° 85.00 



35° 100.00 



40° 115.90 



45° 104.45 



50° 46.20 



55° 17.70 



Both the above tables as well as my own 

 show a general agreement with the chemical- 

 physical law of van't Hoff and Arrhenius 

 (reference 2, below) which states that the 

 velocity of chemical reactions is raised to be- 

 tween two and three times its original amount, 

 whenever the temperature advances 10° C. 



The more recent work of E. D. Sanderson 

 and L. M. Peairs indicates this same relation 

 of temperature to insect life. 



BIBLIOGRAPHY 



1. Snyder, C. D., "On Influence of Temperature 

 upon Cardiac Contraction and Its Relation to In- 



