Half wa y 
1897] NORMAL AND DISEASED ORGANS OF ABIES BALSAMEA 315 
TABLE L. 
CROSS SECTIONS OF LEAVES OF A. BALSAMEA, SHOWING THE DISTRI- 
BUTION OF THE HYPODERMAL STRENGTHENING CELLS. 
Cross sections 
| Leaves of lateral branches 
Leaves of terminal shoots 
a Upper surface. Hypodermal layer con- ne rmal layer 
‘ aon ral.) pigs except where it | broken; Phe sg with ‘ieee 
8 — ated by the sto- | rows of cells. 
a 
nae 
= 2 2. Lower surface. i. eee often Like 1. Often with 2 
g° (Dorsal.) douhie at the midrib to 4 rows of cells at the 
= midrib. 
. 3. At the angles. Pree ig aes lay- Hypodermal layer con- 
a r unbroke sisting of 2 to 3 rows of 
cells. 
ee it 1. Upper surface. Hypodermal cells pres- Hypoderm un broken, 
2 ent, *% more or less | often double rowed. 
ex | isolated. 
Bc | ——$—$ $ 
—e 2. Lower surface. Like 1, but more numer- Like 1, beiy with three 
=2 " ous s, forming > continuous | rows at midrib. 
< layer at midri 
— 
= 5 3- At the angles. Like 1. Layer continuous, often 
in Ueee double rowed 
: 1. Upper surface. dae cells sel- Hypodermal layer often 
= roken by mesophyll and 
3s dom prese en by phy 
“et stomata cells. 
2 Grae a 
© 2. Lower surface. Like 1. Single hg oan Like 1, but never broken 
s often continuous at the —— where it is 
= midrib. often dou 
3. At the angles. Like 1. Hypoderm unbroken. 
$ x I. Upper surface. Hypoderm wanting. » Hypodermal Vs iso- 
5 ea lated when pres 
au 2. Lower surface. Usually 2 to 5 strength- derm continuous 
tor ening cells at the midrib. | at set ng At other parts, 
2 r : cells iso 
2 Slag gue emarecs 
@| 3 At the angles. Hypoderm wanting. 6 to 10 cells 5 oneiens in 
one Casi layer. 
z 1. Upper surface. Hypoderm wanting. Hypodermal ¢ ron scat- 
iS ae tered and iso! when 
aoe AS Co TN at Ra eee present. 
eee oe . 
g2| 2. Lower surface. Hypoderm wanting. a i but with a con- 
i t tinuous layer of 8 to 15 
= ; cells at the midrib. 
EZ ,| 3 At the angles. Hypoderm wanting. 2 to 5 hypodermal cells 
a die usually present. 
