UPWARD TRANSLOCATION OF FOODS IN WOODY PLANTS II7 
Below the lower ring: Starch was fairly abundant in the primary xylem 
and in the inner part of the medullary rays. The medullary rays of the 
outer annual ring were emptied of starch, those of the second contained 
only traces, those of the third still larger amounts, while in the fourth annual 
ring the starch was abundant. 
Check: At the base starch was fairly abundant in the primary xylem 
and in the medullary rays of the inner annual rings, disappearing in the 
third ring and entirely absent in the outer two. Farther out on the stem, 
at a point corresponding to that of the upper ring on the ringed branch, 
the diameter was 20.5 mm. At this point starch was mostly absent from 
the outer nine rings but was fairly abundant in the inner four. Still farther 
out, where the diameter was 12 mm., starch was present in distinct quan- 
tities in the primary xylem only. 
The stems were cut in pieces 12 cm. long, which were then peeled to the 
cambium. These pieces of xylem were centrifuged and the small amount 
of sap obtained was hydrolyzed with hydrochloric acid and tested for re- 
ducing sugar. Samples corresponding to i cc. amounts from the stems 
immediately above the upper ring and between the rings were tested. From 
above the ring 0.3 mg. of cuprous oxide was obtained on boiling with Feh- 
ling's solution, while 2.0 mg. were obtained from between the rings. A 
second test was lost by accident, but at the time of filtering through the 
asbestos there was a very distinct precipitate of the cuprous oxide from the 
sample between the rings and but a very faint trace of the oxide from the 
other sample. Another accident resulted in the loss of the remainder of 
the sap, so no further tests could be made. 
Samples of the oven-dried wood were sawed into 5 mm. lengths and 
extracted in 250 cc. of 80 percent alcohol for 72 hours at 37° C. After 
driving off the alcohol and hydrolyzing with hydrochloric acid by heating 
to 76°, quantitative tests were made for reducing sugar as shown in table 12. 
Table 12. Acer saccharum. Sugars from xylem soluble in 80% alcohol. Hydrolyzed 
extract made up to 100 cc. jo cc. samples tested from between rings and] 
above, 25 cc. samples from the others 
Dry Weight 
of Xylem 
Extracted 
Individual Determinations Expressed 
as Mg. Invert Sugar 
Average of 
Determinations 
Mg. Invert 
Sugar Calcu- 
lated for 25 
Gms. Dry Wood 
Above upper ring .... 
23-33 
31.78 
44.10 
37-07 
14-15 
59-6 
55-55 
40.08 
14.66 
59-85 
54.38 
39.10 
14.58 
59-05 
14.46 
59.5 
54-965 
39-59 
53-91 
155-84 
124.65 
106.80 
From the data shown in table 12 it is evident that the removal of 
soluble carbohydrates from between two rings does not occur or is very much 
retarded. The carbohydrates above the upper ring were very much reduced. 
It is probable that, if a smaller stem had been ringed, the sugar content 
