94 
Notes. 
two or three days \ The last column (96 hours) under the heading II 
of the foregoing table, therefore represents the amount of starch 
contained by these leaves before illumination ; and the details given 
under the heading III describe how much starch there was after two 
to three days and nights. In A, B, C there was some starch, showing 
that starch was being formed but was constantly being reconverted 
into sugar. In D there was more starch, and in E and F much more 
starch : thus showing that starch was being manufactured but that its 
reconversion into sugar was slower than in A, B, C. In G to L there 
was no appreciable change in the amount of starch caused by 
illumination : thus demonstrating that not only was the change of 
starch into sugar retarded but that the manufacture of starch was 
almost or quite arrested. 
Restoring all the leaves into tap-water showed that those which had 
been in A-G were still alive and could make starch, whereas those in 
H-L had been killed. 
The difficulty at once presents itself as to how the change from 
starch to sugar is accomplished in leaves which normally contain 
a considerable amount of acid potassic oxalate in solution. I therefore 
made several series of experiments with leaves of Ox ah's floribunda , 
in which there is a large amount of soluble oxalate. A description 
of one of these series will suffice to show the results obtained. 
Experhnents with Oxalis floribunda. 
Leaves were picked which contained a considerable amount of 
starch. The leaflets were pulled from the petiole and then either cut 
transversely or longitudinally into two halves, or they were only wounded 
by three cuts extending from the margin of the distal or proximal 
part towards the centre of the leaflets. These leaflets were then 
dropped into solutions A-L identical with those used in the Elodea- 
experiments, and into an additional solution (Af) of -5 per cent, acid 
potassic oxalate. The cuts were made in order to allow the solution 
to penetrate the leaves. The leaflets in the respective solutions were 
then kept in darkness for ninety-six hours, at the conclusion of which 
they were examined. Leaflets in A-E , cut in various ways, all showed 
starch only in the actually injured cells at the cut surface. Leaflet in 
F had starch only in a narrow band of cells bounding and running 
1 I unfortunately omitted to record the number of days. 
