The Table of Illustrations at the beginning of the book was created by the transcriber. Inconsistencies in hyphenation such as “extra-ordinary”/“extraordinary” have been maintained. Minor punctuation and spelling errors have been silently corrected and, except for those changes noted below, all misspellings in the text, especially in dialogue, and inconsistent or archaic usage, have been retained. Page 53: “The outer portion of the nucelus” changed to “The outer portion of the nucleus”. Page 54: “the centre of the nucelus” changed to “the centre of the nucleus”. Page 62: “typical forms of arrangement of epidermal calls” changed to “typical forms of arrangement of epidermal cells”. Page 104: “of logwood and santalum rubum” changed to “of logwood and santalum rubrum”. Page 107: “the cross-section of catnip stem (_Nepeta cateria_” changed to “the cross-section of catnip stem (_Nepeta cataria_”. Page 120: “Cross-section sarsaparilla root (_Smilex officinalis_” changed to “Cross-section sarsaparilla root (_Smilax officinalis_”. Page 150: “cells are the narrowest parenchyma cells occuring” changed to “cells are the narrowest parenchyma cells occurring”. Page 155: “Upper epidermis of deer tongue (_Trilisia odoratissima_” changed to “Upper epidermis of deer tongue (_Trilisa odoratissima_”. Page 171: “Parenchyma cells with protuding” changed to “Parenchyma cells with protruding”. Page 193: “grains of paradise (_Amomum meleguetta_” changed to “grains of paradise (_Amomum melegueta_”. Page 237: “Marrubium perigrinum, which is a related species of horehound” changed to “Marrubium peregrinum, which is a related species of horehound”.