CONTENTS 
Xlll 
Pages 
THE STEM. — Definition; direction of growth; functions; size; nodes and 
internodes; stem elongation; duration of stems; stem modifi- 
cations; above ground stems; herb and tree defined; under- 
ground stems; exogenous and endogenous stems 97-101 
STEM HISTOLOGY/ — Annual Dicotyl; Perennial Dicotyl; Exceptional 
Types of Dicotyl Stems; Lenticels and Their Formation; 
Annual Thickening of Stems; Method of formation; “Annual 
. Ring.” Bark: Definition; zones; Periderm; Phelloderm; 
Histology of Cascara Sagrada bark. Wood: alburnum; dura- 
men; microscopic characteristics of Angiospermous and Gym- 
nospermous woods; Histology of Typical Herbaceous Mono- 
cotyl Stems; Histology of Typical Woody Monocotyl Stem . . 101-115 
THE LEAF. — Definition; leaf functions: photosynthesis; assimilation; 
respiration; transpiration 116 
TYPES OF LEAVES DEVELOPED IN ANGIOSPERMS— Cotyle- 
dons; Scale leaves; Foliage leaves; Bract leaves: bracts and 
bracteoles; Sepals; Petals; Microsporophylls; Megasporophyllsn6-ii7 
ORIGIN AND DEVELOPMENT OF LEAVES.— Primordial leaf. Its 
formation 117 
PHYLLOTAXY. — Definition; spiral law of leaf arrangement; alternate; 
opposite, decussate; whorled; fascicled; leaf rank 117-118 
VERNATION. — Definition; inflexed or reclinate; conduplicate; con- 
volute; circinate; plicate; involute; revolute 118-119 
THE COMPLETE LEAF. — Its parts; sessile; petiolate; exstipulate; 
stipulate 1 19-120 
LEAF VENATION. — Furchate; parallel; reticulate; pinni- veined; 
palmately veined; anastomosing veins 120 
LEAF INSERTION. — Definition; radical; cauline; ramal; perfoliate; 
amplexicaul; connate-perfoliate; equitant 120-122 
FORMS OF LEAVES.- — Simple and Compound. ( a ) General Outline: 
ovate; linear; lanceolate; elliptical; oblong; inequilateral; or- 
bicular; peltate; filiform; oblanceolate; cuneate; spatulate; ensi- 
form; acerose; deltoid. ( b ) Apex: acute; acuminate; obtuse; 
truncate; mucronate; cuspidate; aristate; emarginate; retuse; 
obcordate. (c) Base: cordate; reniform; hastate; auriculate; 
sagittate. ( d ) Margin: entire, serrate; dentate; crenate; 
repand; sinuate; incised; runcinate; lobed; cleft; parted; divided. 
Forms of Compound Leaves 122-127 
LEAF TEXTURE. — Membranous; succulent; coriaceous 127 
