1914] GATES—XEROPHILY 471 
water is evaporated from a free water surface as from leaf surface 
on hot days. 
With cuttings somewhat different results were obtained. With 
occasional exceptions, especially on less extreme days, the maximum 
daily transpiration was reached before noon, 2-4 hours before that 
May 1911. May 1911. June 1911. 
6 7 22 23 16 17 
hour 
12 24 12 24 412 24 S@. 23. 1625 4 9 
1.20 . 
g/hr/100 om? Andromeda. 
1.30 
Vac. 
1,00 mac 
g sAndromeda 
-90 
Vac. 
80 mac.’ 
« Aronia 
Andromeda 
ieetosase 
.40Chan. 
oo — 
. Ghameed. * 
20 “rubrum. 
. ro 
emia 
Py Chamae: 
Temperature (ch 
300 
20° 
od 100 % oe 
Transpiration of Cuttings £0 % 
Outdoors. 
Fic. 7.—Transpiration of cuttings of Acer rubrum, Andromeda Agee 
gs 
Aronia Fa BE Chamaedaphne calyculata (from both the Carex and the Chamae 
daphne associations), Larix —— Nemopanthes mucronata, Populus tr emuloides, 
and Vaccinium macrocarpon outdoo 
of the maximum evaporating power of the air. Exceptions were 
more general in shrubs and especially in Chamaedaphne. In this 
species, whose rate of transpiration is low at all times, even in 
cuttings, the maximum transpiration accorded closely with the 
maximum evaporating power of the air. 
