38 GROWTH IN TREES. 
The bast layer measured about 2 mm. in thickness throughout and 
seemed fairly moist. The cork layer measured was light in color, pre- 
sumably had been formed during the current season, and varied from 
0.8 to 1 mm. in thickness. It was easily separable from the older 
darker layers outside of it. The swelling of the bast was complete 
in 2 hours in the acid, 4 hours in the alkali, and about 7 or 8 hours in 
the glycocoll, while increase in water continued for nearly a day. The 
swelling of the new cork in the acid went on at a very slow rate for 
about 2 days, while it continued for 5 days in the alkali. It was com- 
plete in the glycocoll solution in about 10 or 12 hours. 
ae a 4 6AM. 8PM 6AM 6PM 6AM 6PM 6AM 6PM BAM 6PM 6AM. 
1 alo, 
t 28 
mad ‘an ee | ~———| lo. r—— et net 
He +0 
UG. 1) 1919 
28 2 cae 
| nae | “ —— 
ned +8 
MAY _ 26 -|9!9 
aly EY al 
ip ee Pea 
ce f 
PRIL 16 {919 
bo lfay 
Ls C2 
BE AN 
Fia. 15.—Dendrographic records of American beech (Fagus grandifolia), showing only slight 
daily variations in April, increases beginning late in May and continuing until September. 
Separate samples of cork and bast were taken from another place 
on the trunk and sections were tested with the auxograph to ascertain 
the water deficit of these tissues after a week in which growth had 
come to a standstill, presumably on account of the dry, hot days. 
These sections were swelled at 12° C. and the results are as below: 
Solutions. Bast. Cork. 
Water............005 7.5 p. et. 6 p. ct. 
HCl .O1 N...... 2... 10 9 
NaOH OL N......... 22 10 
Glycocoll .01 M...... 15 20 
