10 CONTENTS AND 
CHAPTER XI.— THE STEM, OR ASCENDING AXIS.—69. 
61, Definition, — a, cause of its ascent. 162, Direction horizontal — erect — pro- 
cumbent — ascending — subterranean. 163, Annual—perennial. 164, Distinction 
in regard to size, &c. —a, tree— 4, shrub—e, herb. 165, Most distinctive property 
of stem. 166, Buds. 167, Leaf-bud. 168, The scaly envelopes. a, Scales not 
formed in hot climates, &c.—their design. 169, Bud terminal, develops a simple. 
axis,—a, axillary, developes branches, — 4, adventitious. 170, Branch. 171, 
Thorn, —qa, its nature, &c.—4, distinguished from prickles. 172, Node— inter- 
node, — a, how formed — why the axis diminishes upwards. 173, Arrangement of 
branches, —174, spiral,—a, modifications—circular, how caused. 175, Alter- 
nate —o ite— whorled. 176, Same of the branches. — a, Two classes of stems. 
177, Subterranean —stemléss plants—.varieties. 178, Bulb,—a, tunicated-— 
scaly, —4, how renewed, —c, bulblets. 179, Corm. 180, Tuber. 181, Rhizoma. 
182, Ba og repent stems, their use. 183, Varieties of aerial stems. 184, 
Caulis. 185, Runner. 186, Scape,—a, culm. 187, Vine—a, tendril. 188, Twin- 
ing steras — their direction. 189, Trunk —a, its dimensions. Vote, Ilustrations, 
4, its duration. Vote, Illustrations. 190, Sucker. 191, Offset. 192, Stolon. 193, 
Plurality of trunks — a, Banyan — Mangrove. 
$1. PHYSIOLOGICAL STRUCTURE OF THE EXOGENOUS STEM. —77. 
194, Structure of herbaceous stems — 195, of the first year’s growth of perennial 
stems, — a, basis of the distinction of Exogens and pe ee 196, Exogens. 197, 
Endogens. 198, Parts of the exogenous structure. 1 , Pith. 200, Medullary 
sheath. 201, Wood—number of layers. 202, acre consists of, —a, arrangement 
of its parts. 203, Alburnum—duramen, 204, Medullary rays. 205, Bark, — its 
arts. — 206, its structure — cork —liber. 207, New layer, how formed, — a, outer 
here why shaggy — horizontal fibres, —4, qualities resident in, —o, its peculiar 
vessels. ; 
$2. FUNCTIONS OF THE STEM.—80. 
208, Conveyance of sap, —209, through what portion— its course—elabora~ 
tion — descent. 
§3. OF THE ENDOGENOUS STRUCTURE.—61. 
210, Its peculiarity. 211, Composition. 212, Each bundle consists of, —@, mode 
of increase. 
CHAPTER XIil.— THE LEAF.—82. 
213, Its importance — character. 214, How distinguished. 215, Color—autum- 
nal hues, — a, due to what — chlorophyll — changes, — 4, color of flowers. 
§1. VERNATION. —82, 
216, Meaning of the term—leaf-bud how compacted,—qa, illustration. 217, 
Forms of vernation, — 1, Equitant — 2, Obvolute —3, Involute—4, Revolute — 5, 
Convolute — 6, Plaited— 7, Circinate. 
§2. ARRANGEMENT. —83, 
218, In the bud—after the axis: is developed, —1, Scattered —2, Alternate —3,, 
site — 4, Verticillate—5, Fascieulate. 219, How these forms may be reconciled 
with the spiral, — a, illustration, — 4, Alternate e ea —c, Opposite or whorled 
explained. 220, Leaves radical — cauline — rami 
§3. ORGANOGRAPHY.—#&. 
221, Nature of the leaf—lamina— sessile pega, 222, Petiole—its form — 
1, Compressed — 2, Winged —3, Amplexicaul. 223, General form of the lamina — 
base— apex. 224, Leaf simple— compen 225, Physiology. 226, Venation— 
its organs. 227, Midrib — nerves. , Veins —veinlets. 229, Modes of venation. 
1, Reticulate — 2, Parallel —3, Forked. 230, Varieties of reticulate venation,— 1, 
Feather-veined — 2, Radiate-veined — 3, Varieties of parallel venation. 
ee $4. FORM OR FIGURE. — 86. 
Theory of—form dependent on venation. 232, Forms resulting from the 
