Part 1 — Notes to Chapter I.
Reading edition
The reader will find a further general account of these matters in Sachs' Lectures on the Physiology of Plants, especially Lectures I. and XII., Engl. ed., Oxford, 1887. He may then proceed to Pfeffer's Physiology of Plants, Engl. ed., 1899, chapter I., and to the account of the history of the subject in Sachs' History of Botany, Oxford, 1890, especially pp. 359-375 and 445-524. References to more special literature will be found in Pfeffer.