ITO BOTANICAL GAZETTE [avucusr 
Here again (see fig. 1) we find agreement between the toxic action 
of CaCl, on bacteria with that of the same salt and other calcium salts : 
on animals as shown by Loes (8, p. 425) in the case of Fundulus, and 
by Ostwatp (21) in his work on the freshwater Gammarus. It is’ 4 
well to note here alsothat an examination — 
fe of the. four” curves (fig. 1) for the salts a 
groped Miligams of N employed reveals the fact that CaCl, is ; 
CaCl, solution > easily the most toxic of all for B. subtilis. — 
° 5.60 This fact is of especial interest because q 
; a of its wide disagreement with the facts — 
: hs obtained by experiments on plants with 
5 0.00 CaCl,, in which Macowan (14), for ex-— 
: soos ample, found it to be the least toxic of the — 
four salts for wheat (variety Early Gene- — 
see). In this respect therefore, if B. subtilis may be considered — 
representative, bacteria exhibit the physiological characteristics — 
more typical of animals than of plants, with which they are now — 
classed. We see above, that even at a concentration of 0.3 m J 
CaCl, the formation of ammonia by B. subtilis is inhibited. ; 
SERIES II. POTASSIUM CHLORID > 4 
The experiment was arranged as those preceding it and ec : 
results are shown in table III. : 
On examining the curve (fg. 1) ob: TABLE III 
tained from these results we see at once 
‘ Numbers repre- Milligrams ms of 
the strong resemblance of it to that oe |e Mth 
obtained with the solution of OE” 7 aoa <.60 
although at the concentrations employed : 4.55 
KCI exhibits no stimulating effect, it may : re 
show it at some concentration lower than 4 539 
o.1 m. This general agreement of the 8 287 
chlorids of K and Na has been found to ‘ ee 
be even more striking by Macowan (14) 9 she 
in a_ series. of experiments on wheat. obs 
Here, therefore, B. subtilis exhibits phys- ae hip 
iological characteristics akin to those t4 0.07 
of the higher plants and differing widely 2 oo | 
from those of animals, as shown, ~ for =i tool 
