118 BOTANICAL GAZETTE lAUGUST 
tration employed in the combination. Another interesting case in 
point may be noted in the experiments of the same investigator on 
Polyorchis (11), a jelly-fish of San Francisco Bay. In a solution of 
50°° NaCl + 6°° MgCl, + 1°° CaCl,, the rhythmical contractions 
of the margin go on normally, but with a slight increase of CaCl, 
the contractions are inhibited, and when 5°° of a 3/8 solution of 
CaCl, are added, they are completely suppressed. On the other 
hand, when the margin of the fish, containing the sense organs and 
the central nervous system, is cut off, CaCl, exercises a stimulating 
action on the isolated center of the fish, and contractions will go on 
normally; but when MgCl, is added to the solution, in the ratio of 4 
parts MgCl, to 1 part CaCl,, the stimulating action of the CaCl, is - 
suppressed and contractions cease. In both cases, therefore, there is 
evidence of a definite antagonism between Ca and Mg. Likewise, 
LILLIE (3) proved the existence of antagonism between the two salts, 
when he found that the ciliary activity of the larvae of Arenicola 
would go on normally for some time in a mixture of approximately 
4 parts MgCl, to 1 part CaCl,, whereas it would immediately cease 
if either of the salts at the same concentration was present alone. 
Again, we find the well-known researches of Loew and his pupils 
(12, 13), and later the researches of KEARNEY and CAMERON (1); 
which show in the higher plants the strong antagonism between calcium 
and magnesium, The last-named investigators found, in their expeti- 
ments with the white lupin (Lupinus albus) and with alfalfa (Medicago 
sativa), that when CaCl, was added to MgSO, in about equal propor 
tions, the plants exhibited about 160 times the tolerance for the latter 
salt that they did in solutions of MgSO , alone. They found, further, 
that the antagonism between CaCl, and MgCl,, though not so great 
(increasing the tolerance about 4o times), was nevertheless very 
marked, and where CaSO 4 Teplaced CaCl, the antagonism was Very 
much greater between Ca and Mg than in either of the cases above 
cited. 
I wish to cite only one more case, which emphasizes by strong 
contrast the exceptional results obtained above in experiments with 
B. subtilis; that is, the results of highly ingenious experiments 0° 
rabbits and a monkey by MELTzER and AUER (16) showing the antag” 
nistic effect of calcium on the inhibitory effect of magnesium. As @ 
