is inhibited at high température, almost immediately and 

 very greatly, the other is stimulated rather slowly during 

 the stay at the high température". Apparently Kuyper 

 also distinguishes a favourable and a harmful influence 

 of high températures, which two influences makethemselves 

 felt at a différent rate. 



Thèse quotations sufficiently prove the hypothesis, that 

 the favourable influence of high températures requires 

 time to make itself fuUy felt. On the other hand several 

 exceptions to Blackman's theory may be easily explained 

 in this way. Blackman starts from the supposition, 

 that the intensity of a physiological process after a rise 

 of température immediately assumes the value correspon- 

 ding to that température, and afterwards (if the température 

 in question is a harmful one) only gradually undergoes 

 the harmful influence. As stated above, it has been seen 

 again and again, that the reaction-velocity corresponding 

 to a given high température is not obtained immediately. 

 This explains, why in most cases extrapolation from the 

 time-curves to a time zéro does not give the values to be 

 expected according to van 't Hoff's law. Thèse theoretical 

 values after a time zéro do not exist in reality, as we 

 shall now demonstrate. 



Whén no harmful influence was at work the value 

 corresponding to a given high température (calculated 

 according to van 't Hoff's law) would indeed be reached 

 after some time, but now the harmful influence of the 

 high température has already caused a fall in the intensity 

 of the process before this high value is actually reached. 

 From the beginning the values are lower than would be 

 expected according to Blackman's theory. 



For this reason also it will be impossible to find the 

 theoretical value after a time zéro by extrapolation from 



