76 Pond.—The Incapacity of the — 
dissolved by the alcohol, but this would not affect more than the second — 
decimal place. The figures certainly indicate a negative result, and 
the only possible objection is that mentioned in the preceding experiment, 
namely, the inhibition of enzyme activity by the presence of substances — 
in solution. 
Experiment No. 3. Does an enzyme develop in the endosperm 
during germination? In experiment number 1, the aqueous extract 
was from the resting endosperm. In experiment number 2, the 
endosperm substance was under conditions comparable to those of — 
germination, except that aerobic respiration was impossible and the 
escape of any hydrolytic products could not proceed normally. So it 
seemed best to test the behaviour of endosperms which had been under 
conditions favourable for germination. . For this purpose a quantity of — 
degermed but otherwise whole endosperms was divided into two groups. 
The individuals of group 1 were located on a perforated, floating board 
so that each rested in a thin film of water. The volume of-water which 
floated the board was about twenty litres and this was renewed daily. 
The endosperms were kept sterile by washing them for three minutes 
daily in a one per cent. solution of copper sulphate. The germination of 
a few seeds whose embryos were intentionally left undisturbed was not 
prevented by this treatment. That is, of course, the radicles protruded. 
The individuals of group 2, intended as controls, were placed in crystal 
lizing dishes and enough one per cent. copper sulphate solution added 
to about one half submerge them. This solution was renewed every — 
three days, so as to make the loss by diffusion comparable with that 
occurring in group 1. After twenty-eight days at room temperature, — 
the endosperms were ground and the tannin removed as usual. With 
the powder thus obtained a repetition of experiment number 2 was 
made, except that the residue from 25 cc. of filtrate was determined — 
instead of from 50 cc. The residues of group I were -I1310 and :1360 
grm. Those from group 2 were -1835 and 1883 grm. Evidently 
there is no more manifestation of enzyme in this experiment than in the 
preceding ones. The possibility of the same disturbing factor was not — 
excluded, however, although its potency would necessarily be reduced — 
by the loss of substance from the endosperm during the period under 
conditions of germination. 
The residues are less than one half those found in the preceding 
experiment. This would be expected, as sugar originally present was 
lost by diffusion during the twenty-eight days under germination con- 
ditions. In both cases the copper sulphate residues are larger, and 
since by calculation from the solubility of. copper sulphate in alcohol, 4 
it may easily be seen that not all of the difference can be attributed to _ 
this, it seems quite probable that the escape of sugar from the endosperm — 
SE remerere 
SS SESS ER 
