The following apparent errors have been corrected:

• p. 17 "(see Chap. VI.)," changed to "(see Chap. VI.)."
• p. 40 "actually the case" changed to "actually the case."
• p. 61 "adventititious" changed to "adventitious"
• p. 84 "B. Primrose" changed to "B, Primrose"
• p. 101 "places we do not not need" changed to "places we do not need"
• p. 107 "ordinary leaflets" changed to "ordinary leaflets."
• p. 142 "stem and leaves" changed to "stem and leaves."
• p. 165 "them Did you ever" changed to "them. Did you ever"
• p. 197 "Anther, 80, 81" changed to "Anther, 80, 81"
• p. 198 "179, 152 181" changed to "179, 152, 181"
• p. 199 "without CO₂ 20" changed to "without CO₂, 20"
• p. 200 "twining of petioles, 107" changed to "twining of petioles, 106"
• p. 201 "Seeds, maize, 10" changed to "Seeds, maize, 9"

Archaic or inconsistent language has otherwise been kept as printed.