1904] BERGEN—TRANSPIRATION OF EVERGREENS 287 
the author arrives at a result opposite to that which Durour’ obtained 
from the study of many herbaceous species, but agreeing with the 
results of Jonow.° : 
One species, Neriwm Oleander, has leaves extraordinarily variable 
in size, the smallest being bractlike and only 0.027 the area of the 
largest ones. It did not seem possible to make satisfactory estimates 
of the relative areas of the sun leaves and shade leaves of this 
species. 
All other species examined had shade leaves larger than their 
sun leaves. Exact measurements were made for only four species 
of these, as follows: : 
Ratio of areas 
Sun-+shade 
Citrus Aurantium — - - - : “ * 0.75 
Olea europaea - : : . “ “ - 0.56 
Quercus Ilex (large tree . é fc : 0.44 
Q. Ilex (small bushy ipl) 20 cb . eee 
amnus Alaternus - : : - . 0.68 
The comparisons were based on fairly typical twigs of the same 
age, and all the leaves of each twig, or an equal number of homolo- 
gously situated leaves from each, were examined. 
Baur shapes of the two classes of leaves in question were often 
of the a seey- The ratio of length to breadth for the blades 
bes ts was examined in ten species. In the pinnately compound 
oar islacia Lentiscus there was little difference in the ratios of 
ee &s and shade leaves, whether leaf was compared with leaf or 
with leaflet. The other nine species gave the following results: 
Ratio length+breadth 
Sun Shade 
(r) Arbutus Andrachne _- - - - + 29 2-35 
. A. Unedo ‘ s : : ‘ 3.16 3-21 
- Buxus sem tvirens*  - - - : - 1.97 1.89 
: a eee es 2.04 1.37 
6 “aha a tarentina - - wie, et! stay: 
“Tum Oleander =~ rs 
() 0 kee ee 
=a 
9 , lex (large tree) A eee eee 1.60 
@) ’ (small bushy sapling) B- - - eae | 1.37 
fe us Alaternus fae 2.05 
Oh, DP. 3cr, 
6 Loc. cit., p- 304. 
