580 Brenchley .— The Influence of Copper Sulphate and 
the varying concentration of toxic salt had apparently not influenced the 
actual number of ears produced, but the grains had reached various stages 
of ripeness. The grains from the controls and from the manganese solu¬ 
tions of 1 : 1,000,000 and less were to be regarded as ripe, being hard and 
yellow. The ears resulting from a concentration of 1 : 100,000 M.S. yielded 
a mixed crop, some of the grains being ripe, some half ripe, and others 
green. With 1 : 10,000 M.S. practically all the grains were green. It is 
thus evident that the stronger concentrations of manganese sulphate have 
a definite retarding action on the ripening of the grain in the ear, and the 
indications are that as the strength of the toxic salt decreases this retarding 
influence gets less. Possibly the lowest strengths of the salt have no 
influence in this respect one way or the other. 
On being finally removed from the culture solutions the roots of the 
plants were carefully washed in two or three changes of distilled water to 
remove adherent extraneous salts as completely as possible. The grain 
was shelled out from the ears, and the roots, shoots, and grain were dried 
separately for about three days at ioo° C., all the plants from a similar 
concentration of toxic salt being placed together. It is to be regretted that 
the individual plants were not kept apart and weighed separately, as has 
been done in the more recent experiments. 
The dry weights obtained are shown in the following table :— 
Shoot. 
Root. 
Shoot + Root. 
Grain. 
Shoot + Root + Grain. 
I. 
39-140 
6*282 
45.422 
7.464 
52*886 
2. 
26*670 
4.409 
31.079 
3*852 
34*931 
3 - 
5*020 
42*160 
5*996 
4 8 * j 56 
4 - 
40.565 
5.890 
46*455 
I * 7°9 
48*164 
5 - 
47.900 
5.780 
53.680 
4*635 
5 8 * 3 i 5 
6. 
45 * 9 2 5 
6*630 
52*555 
6*440 
58-995 
A consideration of the total dry weight, including the grain, indicates 
a very considerable depression in (2), which is obviously beyond the limits 
of experimental error. A possible slight depression seems to be shown in 
(3) and (4), and a stimulus in (5) and (6) as compared with the controls. 
As the dry weight of the grain varies so much throughout the series, 
a truer estimate may perhaps be obtained by dealing only with the dry 
weights of the roots and shoots, which are fairly comparable. 
A rather different estimate of the state of the case is obtained from 
these figures. The striking depression with 1 : 10,000 M.S. is still evident, 
and also a possible slight depression with (3) 1 : 100,000 M.S., but in (4) the 
apparent depression was due to the failure of the grain, as the new figures 
show that this concentration has little effect upon the growth, the balance 
possibly being in favour of a slight stimulus. The stimulative effect of (5) 
and (6) is real. 
