CONTENTS. 



PART IV.— Growth. 



Lecture XXVI. — The Distribution of the Phases of Growth in Space and Time . 41 1 

 The Growth of Plants compared with that of Crystals. — The Three Phases of 

 Gro\vth. — Embryonic Conditions of Organs. — Elongation of Organs. — The Com- 

 pletion of Internal Differention in Organs. — Distribution of Growth in Non-Cellular 

 Plants. — Growth of Fungi. — Growth of Algse and Myxomycetes. 



Lecture XXVIL — Relations between Growth and Cell-division in the Embryonic 



Tissues 431 



Dependence of Divisions on the Form of the Mother-cell. — The Arrangement of 

 Cells Independent of the Morphological and Physiological Nature of the Organ. — 

 Net-works of Cell-walls. — Periclines, Anticlines, Trajectories. — Arrangement of Cells 

 in an Elliptical Disc. — Examples agreeing with the Diagram. — Sequence of Anti- 

 clines and Periclines immaterial. — Displacement of Division-walls by Growth. — 

 Anticlines and Periclines in an Ellipsoidal body. — Anticlines and Periclines in 

 Growing-points. — The Apex of the Growing-point grows most slowly. — Confocal 

 and Co-axial Arrangement of Cells. — Apical Cells. — Transverse Segments of Apical 

 Cells. — Tetrahedral Apical Cells. — Significance of the Apical Cell. 

 Lecture XXVIIL — Formation of Organs at the Growing-point. Branching . 460 

 Forms of Growing-points. — Depressed Growing-points. — Metamorphosis of Growing- 

 point into an Organ. — Progressive Development of Organs at the Growing-point. — 

 Development of Leaves. — Development of Intemodes. — Shoots with and without 

 Branches. — Dichotomy or Bifurcation. — Apparently Endogenous Inception of Shoots. 

 Adventitious Growing-points. 



Lecture XXIX. — Axis of Growth. Polarity. Laterality. Relations of Position 481 

 Axis of Growth. — Polarity in the Growing Axis. — Radial, Bilateral, Dorsi-ventral. — 

 Extension of the idea of Radial Structure. — Dorsi-ventral, Bilateral. — Dorsi- 

 ventrality. — Dorsi-ventral Shoots. — Laterality and Phyllotaxis. — Rejection of the 

 Spiral-theory. — Parastichies. — Divergences. 



Lecture XXX. — Causal Relations of Growth of the different Organs of the Plant 



one to another (Correlations) 502 



Conception of the Form of Plants. — Influence of Growing Shoots on other Shoots. — 

 Bud-scales are suppressed Foliage-leaves. — Organs of like kind as Competitors 

 for the same Formative Substances. — Assimilatory Tissue forms thin Lamellae. — 

 Assimilating Surfaces influence the Formation of Wood and Roots. — The Activity 

 of the Roots affects the Functions of Leaves. 



Lecture XXXI.— Influences of the Environment on the Processes of Configura- 

 tion in the Plant 515 



Inherited Disposition and External Influences. — Influence of Gravitation on the 

 Origin of Growing-points. — Influence of Gravitation on the Orientation of Growing- 

 points. — Movement of Shoot-forming and Root-forming Substances. — Development 

 of Roots on the side turned away from Light. — Dorsiventral Structure induced by 

 Illumination.. — Influence of Light and Gravitation on Post-embryonic Growth. — 

 Influence of Gravitation on Post-embryonic Growth. — Influence of Light on Post- 

 embryonic Growth. — Etiolation. — Flower-forming Reserve Substance in Bulbs, 

 Tubers, &c. — Influence of Light on Post-embryonic Growth. — Gall-formations. — 

 Fertilisation. 



Lecture XXXII. — The Course of Growth during Elongation. Periodic Varia- 

 tions 539 



The Grand Period of Growth. — Distribution of Growth in the Growing Region. — 

 Length of the Growing Region. — Passive Motion of the Apices of Buds and Roots. 

 —Nutations due to Unequal Growth. Torsions due to Growth. — Growth by Day 

 and by Night. — Auxanometer. — Daily periods of Growth. — Daily periods in con- 

 tinued darkness. — Apparatus for Auxanometrical observation. 



