[7] G. H. Carpenter: “Insects: Their Structure and Life,” p. 300.
[8] W. B. Bottomley in “The Exploitation of Plants,” edited by F. W. Oliver, 1917, p. 12.
[9] To be accurate, certain groups of Bacteria, the lowest forms of organized life, must be excluded. They appear capable of building up their bodies directly out of inorganic substances.
[10] F. J. Hanbury and E. S. Marshall: “Flora of Kent,” 1899, p. xxxv.
[11] A. F. W. Schimper: “Plant Geography” (English translation, 1903), p. 719.
[12] A. F. W. Schimper: “Plant Geography” (English translation, 1903), p. 41.
[13] See Agnes Arber: “Aquatic Angiosperms: the Significance of their Systematic Distribution,” Journal of Botany, 1919, p. 83.
