ANTAGONISM 



143 



ment. The values of the velocity constants which are 

 thus obtained, are given in Table X. 



It is evident from Table X, that as the per cent, of 

 CaCl 2 in the mixtures increases (beginning at 1.41% 

 CaCl 2 ) the value of K M first falls and then rises, its 



locx 



25 



75 HOURS 



FIG. 60. Curve of net electrical resistance of Laminaria agardhii in 95.24 NaCl + 4. 76 



CaClj (unbroken line) the trial curve (broken line) calculated from the velocity constants KA 



= .000245 and KM =.00590. Each observed point represents the average of six or more 



experiments: probable error of the mean less than 10% of the mean. All readings were 



made at 15 C. or corrected to this temperature. 



minimum value occurring in 97.56 NaCl + 2.44 CaCl 2 

 (which is the mixture in which the tissue lives the long- 

 est.). It seems reasonable to assume that in each 

 mixture a substance is formed which reduces the value 



of K M . We may assume that the decrease of K M is directly 



proportional to the amount of this substance, which may 

 be assumed to occur in maximum amount in 97.56 NaCl + 

 2.44 CaCl 2 . 



The simplest assumption which we can make is that 

 NaCl and CaCl 2 combine with some constituent of the 



