Note 26 — Chapter XXIII · DIRECT AND DEFINITE ACTION OF THE EXTERNAL CONDITIONS OF LIFE.
Reading edition
See Lecoq, on the Villosity of Plants, ‘Géograph. Bot.,’ tom. iii. pp. 287, 291; Gärtner, ‘Bastarderz.,’ s. 261; Mr. Masters on the Opuntia, in ‘Gardener’s Chronicle,’ 1846, p. 444.