1920] 



SHULL— SEEDS 



383 



* 



origin, they offer the best possible opportunity to study the ques- 

 tion of straight line plots of logarithms against temperature. These 

 are shown in fig. 4. It is 

 seen that they are decidedly 

 not straight lines. 



Having now presented in 

 some detail the results of the 

 mathematical analysis of the 

 data, which has been carried 

 out in such a way as to make 

 possible a comparison be- 

 tween this work and that 

 of Brown and Worley, I 

 shall discuss briefly the sig- 

 nificance of the results. 



5 



!0 



15 20 25 30 35 



Fig. 4. — Logarithms of velocity plotted 

 against temperature, split peas, table XV. 



Discussion 



There are several features of the work by Brown and Worley 

 which need to be considered in judging its value. Attention 

 was called in the introduction to the rather rough method of 



which, however, was quite skilfully used. 



tangents 



securing 



In view of the fact that the early phases of absorption were not 

 studied by them, however, it is possible that the tangents they 

 obtained between the point of origin and the first intake data at 

 each temperature would not agree with those of a curve plotted at 

 close intervals. If the barley seeds were to show a large initial 

 intake, the curve would be thrown upward from the base, and the 

 succeeding portion of the curve would have a different course, 

 affecting the very portion of the curve where the tangents are 

 measured in determining intake velocities. It is this early part of 

 the curve which is important, for the tangents are measured for 

 that part of the curve between the origin and 25 per cent of intake. 

 The greatest disadvantage in the data supplied by Brown and 

 Worley is the long time interval between observations, and espe- 

 cially the long first interval. Their first observations were taken 

 at 5-6 hours after the beginning of absorption. If I had waited 

 5 hours for the first observations in any of the work presented 



