Effect of Temperature on Biological Rates 



153 



is higher in warm weather and lower in cool weather (Fig. 5.10). 

 This relationship was put to use by a blind astronomer who was able 

 to "read' the temperature by timing the chirps produced by the crickets 

 outside his house and applying a formula that he had worked out 

 ( number of chirps in 13 sec -f- 42 = °F ) . 



Another example of the increase in reaction speed caused by rise in 

 temperature is given in Table 10. The data show that the cod egg will 

 develop at a temperature as low as — 1°C. Its speed of development 

 increases regularly to a temperature of 14°C, above which the egg 

 will no longer survive. The relationship with temperature in this 



100 



220 



140 180 



Stridulations per minute 



Fig. 5.10. Relation of stridulation rate of tree cricket Oecanthus to temperature 

 and also to pitch. The note C is "middle C." ( Modified from Matthews, 1942, 



Science. ) 



TABLE 10 



Relation between Temperature and Rate of Development of Eggs 

 OF A Cold-Water and A Warm-Water Fish 



