X CONTENTS. 



PAGE 



Lecture IX.— Systems of Tissue, continued. Fundamental Tissue. Rudimentary 



Differentiations of Tissue '4i 



FundamentalTissue.—Hypoderm.— Sheaths.— Sclerenchyma.—Assimilatory Paren- 

 chyma.— Tissue-systems of Mosses.— Differentiations of Tissues in AlgK. — Differ- 

 entiations of Tissues in Fimgi. 



Lecture X.— Secondary Growth in Thickness of Shoot- Axes and Roots . . 1 55 

 Correlation between Growth in Thickness and extent of Foliage.— Cambium-ring.— 

 Products of Cambium.— Wood.— Heart-wood and Alburnum.— Cork, Periderm.— 

 Bark.— Leuticels.— Secondary Growth in Thickness of Monocotyledons. 



Lecture XL — Laticiferous Vessels and Receptacles for Secretions . . . 171 

 Latex-tubes.— Variety of Secretions.— Calcium Oxalate.— Calcium Carbonate.— 

 Secretion-vesicles. — Resin- and Gum-canals. — Internal Glands. — Epidermal Glands. 



PART II. — The External Conditions of Vegetable-life, and the 

 Properties of Plants. 



Lecture XII. — The General External Conditions of Plant-Life .... 189 



Organic Structure and External Influences. — Cardinal Points of Temperature 

 suitable for Vegetation. — Representation of the Dependence by Curves. — General 

 Law of Dependence. — ^Dependence on Light. — Daily Periodicity.— Influence of 

 Gravitation, Light, Electricity. — Dependence on Habitat. — Dependence on Animals. 



Lecture XIIL— The Molecular Structure of Plants and its Physiological Im- 

 portance 205 



Molecules, Molecular Complexes. — Swelling. — Diosmosis. — Turgescence. — Artificial 

 Cells. — Tissue-tensions. — Rigidity due to Tissue-tensions. — Elasticity, &c. due to 

 Lignified Sclerenchyma. 



PART III.— Nutrition. 



Lecture XIV. — The Ascent of Water in Transpiring Land-Plants . . .225 



Importance of the Water-current in Nutrition. — Transpiration from Leaves. — 

 Ascending Current in the Wood. — Sclerenchyma conducts water. — Distribution of 

 the Water-current in the Leaves. — Rapidity of the Upward Flow. — Filtration 

 through Wood. — Condemnation of the Capillarity Theory. — Calculation of the 

 Cubic Contents of the Wood-cavities. — Specific Properties of Wood. — Suction in 

 Cut Branches. 



Lecture XV. — Conditions of Transpiration— Absorption of Water and Nutritive 



Matters by the Roots of Land-Plants 246 



Regulation of Transpiration. — Mechanics of Stomata. — Stomata as the Regulators of " 

 Transpiration. — Transport of Nutritive Salts in Wood. — Absorption of Water and 

 Salts by Leaves. — Water contained in the Soil. — Absorption of Water by Root- 

 hairs. — Absorption of Substances held in the Soil. — Attachment of Root-hairs to 

 Particles of Soil. — Corrosion of Minerals by Roots. 



Lecture XVI. — Excretion of Water in the Liquid State 266 



Mobility under Pressure of the Water in Wood.— Water-currents in the Wood due 

 to Changes of Temperature. — Weeping of Root-stock.— Periodic variations in the 

 Excretion of Water.— Mechanics of the Weeping of Root-stocks.— Relation of Root- 

 pressure to Transpiration. — Excretion of Drops from Leaves, — Excretion of Drops 

 by Non-cellular Plants. 



