320 BOTANICAL GAZETTE [ NOVEMBER 
TABLE IL—Continued. 
Leaf structures Normal leaves Diseased leaves 
Always present. Cells Nearly always present. The 
j ym. 
have bordered pits only. lignified parenchyma cells 
Transfusion tissue of Cells lignified. unequally thickened. Cells 
rcle. 
the pericy have simple as wellas bordered 
pits. Bordered pits larger 
than normal. 
Lignified parenchyma cells Lignified; more irregular 
varying in size and thickness | in form and size. Larger and 
of their walls. Found on | thicker walled than in normal. 
ih cease both sides, but mostly on the Cells often fiber like. 
: dorsal side of the bifurcated 
bundle. 
Non-pitted paren- 
e peri- 
Phloem and xylem consist- Phloem and xylem less 
ing of from 5 to 10 rows of | developed than —— 
‘ cells. Rows usually separ- | The cells are often larger an 
TR TE. ated by medullary rays, the | thicker walled. 
| cells of which contain crystals Medullary rays and crystals 
of calcium oxalate. of calcium oxalate are absent. 
eh 
IV. ANATOMY OF THE NORMAL AND DISEASED BUDS. 
1. Normal buds.—The buds of A. balsamea are conical or 
globular. In winter condition they are covered by a layer of 
resin 1 to 2™™ thick at the apex of the bud. The bud scales 
are destitute of any epidermal hairs, but the edges of the outer 
exposed scales, as well as the inner ones, are fringed with — 
ginal hairs. The number of bud scales does not vary much in 
different buds, the smaller and lateral ones usually having the 
same number as the larger and terminal ones. The scales of the 
terminal buds are relatively larger. 
The epidermal cells of the outer surface (morphologically 
the under surface) of the exposed scales are usually oblong, and 
2 to 8 times as long as broad, usually with oblique ends. - 
viewed from the exterior, and in cross sections, they are found 
to be about twice as deep as broad, which is due mainl 
the thickened outer wall of the exposed epidermal cells. 
exposed cell wall; hence, the outer wall of each epiderma 
y to 
thickening of the outer wall is greater in the center Me — 
: posm 
