122 BOTANICAL GAZETTE [AUGUST 
and a freshwater Gammarus respectively, that a distinct antagonism : 
exists between NaCl and KCI. Among plants we find that the work — 
of OsTERHOUT (20) also shows some antagonism between KCI — 
and NaCl, and here again it is significant to note that there are 
two maxima. : 
The curve in jig. 5 shows an unusually g eradual rise and decline. 
AOme 
167729. 
lkltg | 
Cm? + 
Nat/ 
BST ff C F - ao 57% 
—Antagonism curve, NaCl vs. KCl. The ordinates at K represent the 
ammonia phone in milligrams formed in a pure NaCl solution. The o din: ate at ‘ 
the ordinates at the intermediate points represent the amounts formed in various — 
combinations of the two salts as indicated by the corresponding letters in table Ix. 
This is characteristic of the Na and K chlorids used singly, where — 
they become gradually more and more toxic with the increase of eee md 
centration. It is consequently in strong contrast to the sharp 4 G 
of the calcium and magnesium curves, especially that of the former — 
In this curve, as above noted, there are two maximal points, one ata 
the combination of 1o0°* of NaCl + 5°¢ KCl, and another at the 
and — 
combination of too°¢ KCl + s50°° NaCl. In three confirmatory — 
series on this experiment, the maximal points were in each cat 
obtained at the same combinations. 
