374 



BOTANICAL GAZETTE 



[may 



can be successfully applied to all cases of absorption, or that it has 

 any special significance beyond its applicability to measuring 

 tangents accurately in all curves to which it fits. 



In dealing with the data of table I it was found desirable to 

 partially combine the two series at 5 C. because of irregularities 

 in each set. As the seeds used in these early tests were not reduced 

 to water temperature before immersion, some tests were run for 



TABLE VIII 



Algebraic curves for absorption data; intake in percentage of air-dry 



weight (Xanthium) 



Time 



1 minute 



15 minutes 



30 minutes 



45 minutes 



60 minutes 



75 minutes 



90 minutes 



105 minutes 



120 minutes 



135 minutes 



150 minutes 



165 minutes 



180 minutes 



195 minutes 



210 minutes 



225 minutes 



240 minutes 



270 minutes 



300 minutes 



330 minutes 



360 minutes 



26 hours . . 



20°C 



Data low Computed 



• • 



t * 



9 4 



i-73 



17.38 

 20.20 



25.12 



31.06 

 32.80 



3743 

 38.52 



39-39 

 40.98 



42.57 



43-95 



44-75 

 47.28 



1. 821 

 6.481 



IO-599 

 14. 213 



17.396 



20. 239 



22.809 



25-153 

 27.308 



29.301 



31.157 

 32.891 



34.520 

 36.056 



37.507 

 38.884 



40.194 

 42.634 



44.871 



46 . 93+ 

 48 . 849 

 84 . 280 



Data high 



6.806 

 II.OO 



14-55 



Time 



22.81 



2744 

 29.32 



34.54 

 36.13 



1 



15 



30 



45 

 60 



75 

 90 



105 

 120 



135 

 150 

 180 



7 



minute. . 

 minutes. . 

 minutes, 

 minutes . . 

 minutes. . 

 minutes. . 

 minutes. . 

 minutes. . 

 minutes., 

 minutes. . 

 minutes . . 

 minutes., 

 hours. . . . 



35° C 



Data low 



2.45 



16.41 



30.21 



Computed 



39.80 

 41.87 



43-25 



45.24 

 48.46 



* 



2.840 

 10.136 



16.471 

 21 .720 



26.317 



30 ■ 305 



33.855 



37-Q54 



39 • 964 

 42.635 



45- 102 



49 - 534 

 72.348 



Data high 



IO.89 



2I.8I 

 26.38 



33 -89 



37- H 



with seeds at water temperature 



The 



result was a slight lowering of the initial intake at 5 C, and an 

 increase at 35 C. These corrections were taken into consideration 

 in deriving the values of the constants for computing the theoretical 

 intake from the formula. 



In the 5 C. curve the values for the constants a, b, and c in the 

 equation given are as follows: y = 48. 5 log IO (o.oo8x+ 1)4-0.85. 

 The closeness of the intake computed from this equation to the 

 actual data is illustrated in tables VII and VIII. 



