122 



BOTANICAL GAZETTE 



TABLE VT 



Wheat 



[FEBRUARY 



Since each molecule of K,S04 yields two K ions, half as much K.SO^ is used as KCl or KNO, . 

 The figures for 50 K.SO4+S0 H,0 are comparable with the corresponding figures for KCl and KNO3, 

 though the concentration of the solution is only half as great. For example, the roots reach a length 

 of 80""° in soe« K,S04 .o937«+soee H,0; a length of 216"" in 50" K.SO^ .osm + so«* H,0; and 

 a length of 276"™ in 50" KjSO, .037sw+so« H.O. 



It will be noticed that these antagonistic effects are less marked as 

 the concentration is lowered. This is of course true of all antago- 

 nistic action, since as the concentration is lowered toxicity diminishes 

 and the effect of its inhibition is consequently less striking. 



It is observed that those parts which are in direct contact with 

 solutions always show their effects much more plainly than those 



