434 



M. H. JACOBS 



TABLE 2 



Theoretical amounts of injury inflicted on starfish larvae at various temperatures. 

 The fatal exposures are taken from column 1 of table I 



relation that exists between the amounts of injury inflicted in 

 unit time at different temperatures is 



ip = loQ? 



where lo is the amount of injury inflicted at the temperature 

 chosen as the standard for comparison, and Ip the amount 

 inflicted at any other temperature separated from the first one 

 by p degrees. If the second temperature is lower than the 

 first, p, of course, has a negative sign. Of the two constants in 

 the above expression, Qi may in general be taken for starfish 

 larvae with sufficient accuracy as equal approximately to 2, 

 and lo may be determined experimentally for a given lot of 

 organisms for any convenient temperature, preferably a rather 

 low one, as the percentage of error is then less. Having these 

 two constants, it is possible to calculate not only the amount of 

 injury that would be inflicted by an exposure of any length to 

 any temperature to which the above equation applies, but like- 

 wise the amount of injury that ought theoretically to be in- 

 flicted during a gradual rise from room temperature to any 

 desired temperature. In the latter case, the amount of injury 

 would be represented graphically by the area of the curve: 



y = a Qf 



