XII 
CONTENTS 
Pages 
TRACHEARY TISSUE.— Tracheae: Definition, function and classifica- 
tion; Tracheids: Definition and function 78-80 
MEDULLARY RAYS. — Primary and Secondary; their distribution and 
functions 81 
FIBRO-VASCULAR BUNDLES. — Definition of the various types; 
the distribution of each type; Xylem and Phloem 81-8,} 
SECRETION SACS. — Definition and distribution 83 
INTERCELLULAR AIR SPACES. — Definition ; schizogenous and lysi- 
genous air spaces; their relative size 83 
SECRETION RESERVOIRS. — Definition; structure; internal glands; 
secretion canals 84 
CLASSIFICATION OF TISSUES ACCORDING TO FUNCTION. . 84 
CHAPTER VII 
Plant Organs and Organisms 
PLANT ORGANS AND ORGANISMS.— Organ and organism defined. 
Vegetative Organs: Roots, stems and leaves. Reproductive 
Organs: Flower, fruit and seed. Embryo and its parts; function 
of the cotyledon 85 
THE ROOT. — Definition; functions; root hairs; root cap; generative 
tissues; differences between root and stem ' 85-87 
CLASSIFICATION OF ROOTS AS TO FORM— Primary root; tap 
root; secondary roots; fibrous and fleshy roots; anomalous 
roots; adventitious roots; epiphytic roots; haustoria 87-88 
CLASSIFICATION OF PLANTS ACCORDING TO DURATION 
OF ROOT. — Annual; Biennial; Perennial 88 
ROOT HISTOLOGY. — A. Monocotyledons. B. Dicotyledons; Histology 
and Development of the California Privet root; Abnormal 
structure of Dicotyl roots; Histology of a Dicotyl Tuberous 
Root, Aconitum 88-93 
ROOT TUBERCLES. — -Definition; occurrence on roots of Leguminosae, 
Myricaceae, etc.; their etiology 93-96 
THE BUD. — Definition; plumule, scaly buds, naked buds; Classification 
of Buds According to Position on Stem: terminal bud; 
axillary or lateral bud ; adventitious bud ; accessory bud. Classi- 
fication of Buds According to Development: leaf bud; flower 
bud and mixed bud. Classification of Buds According to 
their Arrangement on the Stem: alternate; opposite; whorled . 96-97 
