UPWARD TRANSLOCATION OF FOODS IN WOODY PLANTS 121 
solution was filtered off, the alcohol was removed by repeated evaporation, 
and the solution was finally boiled for 3 minutes with 10 percent hydroch- 
loric acid, neutralized, and made up to 200 cc. The amounts of sugar found 
are shown in table 17. 
The residues were shaken up with 250 cc. of water and 0.2 gm. taka 
diastase. After 12 hours the sawdust still contained abundant starch. 
The material was then placed in a steam autoclave at 15 pounds pressure 
for 45 minutes. Two-cubic-centimeter samples diluted with 5 cc. of water 
and tested with iodine showed deep blue in the sample from between the 
rings and very faint traces of blue in those from the check and from above 
the rings. Five tenths of a gram of diastase was added to each and left 
18 hours, but on examination starch was still present in the sawdust and 
in the small sections of wood. The material was then autoclaved a second 
time at 15 pounds for 10 minutes. On testing the extract as before, only 
that from between the rings clearly showed the presence of starch. 
Without attempting to extract more of the starch, the solutions were 
filtered off and digested with 0.25 gm. of taka diastase. Each of the extracts 
was then made up to 500 cc. and 25 cc. samples were tested for sugar. This 
is expressed in the table as maltose, but it is very probable that much of it 
was really glucose. Relative values, however, are all that are necessary. 
Table 18. Fagus grandiflora. Sugar obtained from residue by heating under pressure 
and digesting with diastase 
Single Determinations 
Expressed as Maltose 
Average 
Total Sugar Present in 
50 Gms. Dry Wood 
Expressed as Maltose 
46.03 
40.24 
43-14 
862.80 
51.46 
52.46 
51.965 
1039.30 
Between rings 
89.25 
89.78 
89.52 
1790.40 
Discussion 
The experiments with ringing accompanied by removal and non-removal 
of leaves clearly show that some substance necessary for growth passes 
upward through the phloem and that, if the leaves remain above a ring, 
they are able to supply some of this substance. This substance may func- 
tion as a food, supplying building material and energy, or it may function 
merely as an osmotically active agent, thereby enabling the tissue to com- 
pete successfully for water, or, as is more probable, it may function in both 
roles. Analyses show that ringing when leaves are removed results in a 
decrease both of osmotic pressure and of sugar content. Removal of leaves 
without ringing also decreases the osmotic pressure and the sugar content 
below those of the normal stem with leaves. The data obtained are not 
sufficient to enable one to determine with any degree of assurance whether 
sugar is the only or even the chief substance concerned. 
