1. Schenck, H. (1885) gives the ranges of a long series of aquatic plants, as far as they were known at that date. Schenck, H. (1885). Die Biologie der Wassergewächse. Verhandl. des naturhist. Vereines d. preuss. Rheinlands, Westfalens und des Reg.-Bezirks Osnabrück, Jahrg. 42 (Folge v. Jahrg. 2), 1885, pp. 217–380, 2 pls.
[This memoir, in conjunction with Schenck, H. (1886), forms one of the most important general contributions ever made to the study of water plants; it summarises the state of knowledge of a generation ago. Many of the more recent accounts of this biological group are based on Schenck's work.]

 

 

 

 

 

2. Gin, A. (1909). Recherches sur les Lythracées. 166 pages, 13 pls., 28 text-figs. Thèse Doct. Univ. Paris, 1909.
(This memoir contains information about the structure, distribution, etc. of the aquatic Lythraceae.)

 

 

 

 

 

3. Weddell, H. A. (1872). Sur les Podostémacées en général, et leur distribution géographique en particulier. Bull. de la Soc. bot. de France, T. xix. 1872, pp.50–57.
(This paper is based upon the author's own observations in Brazil. Stress is laid upon the very local distribution of many of the Podostemaceae.)

 

 

 

 

 

4. This paradox was noted by Darwin, C. (1859). On the Origin of Species. ix + 502 pp. London, 1859.
(Chapter xii. contains a section dealing with the distribution of fresh-water animals and plants, pp. 383–388.)

 

 

 

 

 

5. Candolle, Alphonse P. de (1855). Géographie Botanique. Paris, T II. 1855.
(Pages 998–1006 deal with the distribution of aquatic species. After showing how widely these plants are distributed, the author concludes that the facts are scarcely explicable except on the ground that there have been multiple centres of creation.)

 

 

 

 

 

6. Reid, C. (1892). On the Natural History of Isolated Ponds. Trans. Norfolk and Norwich Nat. Soc. Vol. V. 1894 (for 1889–1894). Part 3, 1892, pp. 272–286.
(This paper is chiefly based on a study of the dew ponds of the South Downs. It forms an important contribution to the subject of the methods of dispersal of water plants.)

 

 

 

 

 

7. Guppy, H. B. (1906). Observations of a Naturalist in the Pacific between 1896 and 1899. Vol II. Plant-dispersal. xxviii + 627 pp., I pl. London, 1906.
(The water-side plants of the British flora are considered in Chapters III and IV; Note 10, pp.535–538, records the degree of buoyancy of the seeds and seed vessels of more than 300 British plants, including a large number of aquatics. The book also contains numerous other notes on water plants, e.g. distribution of Naias, p. 367.)

 

 

 

 

 

8. Dr. Guppy has suggested to the writer "that the permanent headsprings of rivers in elevated regions where the sources of rivers may lie in proximity would serve as centres of dispersion for the same plants in different river-basins, and if that is right then the species held in common ought to include all those growing in the head-springs, e.g. in England, Callitriche aquatica, Nasturtium officinale, Ranunculus aquatilis, etc., etc." (By letter, February 3rd, 1918.)

 

 

 

 

 

9. Guppy, H. B. (1906). Observations of a Naturalist in the Pacific between 1896 and 1899. Vol II. Plant-dispersal. xxviii + 627 pp., I pl. London, 1906.
(The water-side plants of the British flora are considered in Chapters III and IV; Note 10, pp.535–538, records the degree of buoyancy of the seeds and seed vessels of more than 300 British plants, including a large number of aquatics. The book also contains numerous other notes on water plants, e.g. distribution of Naias, p. 367.)
See also Praeger, R. L. (1913). On the Buoyancy of the Seeds of some Britannic Plants. Sci. Proc. Royal Dublin Soc., N. S., Vol. xiv, 1913–1915, pp. 13–62

 

 

 

 

 

10. Fauth, A. (1903). Beiträge zur Anatomie und Biologie der Früchte und Samen einiger einheimischer Wasser- und Sumpf-pflanzen. Beihefte zum Bot. Centralblatt, Bd. xiv. 1903. pp. 327–373, 3 pls.
(The fruit and seeds of Alisma, Elisma, Sagittaria, Butomus, Callitriche, Hippuris, Myriophyllum, Limnanthemum, Menyanthes and Littorella are dealt with, and certain land plants are included for comparison.)

 

 

 

 

 

11. Guppy, H. B. (1893). The River Thames as an Agent in Plant Dispersal. Journ. Linn. Soc. Bot. Vol. xxix. 1893, pp. 333–346.
(An account of observations upon river drift in the Thames, Lea and Roding, with a discussion of the part played by birds in the dispersal of aquatic plants.)

 

 

 

 

 

12. Darwin, C. (1859). On the Origin of Species. ix + 502 pp. London, 1859.
(Chapter xii. contains a section dealing with the distribution of fresh-water animals and plants, pp. 383–388.)

 

 

 

 

 

13. Reid, C. (1892). On the Natural History of Isolated Ponds. Trans. Norfolk and Norwich Nat. Soc. Vol. V. 1894 (for 1889–1894). Part 3, 1892, pp. 272–286.
(This paper is chiefly based on a study of the dew ponds of the South Downs. It forms an important contribution to the subject of the methods of dispersal of water plants.)

 

 

 

 

 

14. Wheldon, J. A. and Wilson, A. (1907). Information relating to this experiment has been most kindly supplied to me by letter by the authors, to supplement that recorded in their Flora of West Lancashire.
The Flora of West Lancashire. 511 pp., 15 pls., 1 map. Eastbourne, 1907.
(On p. 339 a reference is made to a pond which was dug experimentally in order to see what water plants would colonise it.)

 

 

 

 

 

15. Duval-Jouve, J. (1864). Lettre sur la découverte du Coleanthus subtilis en Bretagne. Bull. de la Soc. bot. de France, T. xi. 1864, pp. 265, 266.
(Notes on the part played by birds in the dispersal of aquatic plants.)

 

 

 

 

 

16. West, G. (1910). A Further Contribution to a Comparative Study of the dominant Phanerogamic and Higher Cryptogamic Flora of Aquatic Habitat in Scottish Lakes. Proc. Roy. Soc. Edinb. Vol. xxx. 1910. (Session 1909–1910), pp. 65–181, 62 pls.
[A continuation of West, G. (1905).]

 

 

 

 

 

17. Meister, F. (1900). Beiträge zur Kenntnis der europäischen Arten von Utricularia. Mémoirs de l'Herbier Boissier, No. 12, 1900, 40 pp., 4 pls.
(A systematic account with biological notes.)

 

 

 

 

 

18. Im Thurn, E. F. (1883). Among the Indians of Guiana. XVI + 445 pp., 10 pls., 43 text-figs., 1 map. London, 1883.
(This book contains references to the Podostemaceae and Victoria regia living in Guiana waters.)

 

 

 

 

 

19. Willis, J. C. (1902). Studies in the Morphology and Ecology of the Podostemaceae of Ceylon and India. Ann. Roy. Bot. Gard. Peradeniya, Bol. I. 1902, pp. 267–465, 34 pls.
(An important general work dealing with the structure and biology of this group.)

 

 

 

 

 

20. Caspary, R. (1870²). Welche Vögel verbreiten die Samen von Wasserpflanzen? Schriften d. könig. phys.-ök. Gesellsch. zu Königsberg, Jahrg. XI. 1871 (for 1870), Sitzungsber. p.9. (This note emphasizes our ignorance of the part played by water birds in the distribution of water plants.)

 

 

 

 

 

21. Weddell, H. A. (1849). Observations sur une espèce nouvelle du genre Wolffia (Lemnacées). Ann. des sci. nat. Sér. III. Bot. T. 12, 1849, pp. 155–173, 1 pl.
(The author discovered in Brazil a minute species of Wolffia, which he named W. brasiliensis. Twelve of the flowering plants could be accommodated on one frond of Lemna minor.)

 

 

 

 

 

22. Darwin, C. (1859). On the Origin of Species. ix + 502 pp. London, 1859.
(Chapter xii. contains a section dealing with the distribution of fresh-water animals and plants, pp. 383–388.)

 

 

 

 

 

23. Guppy, H. B. (1893). The River Thames as an Agent in Plant Dispersal. Journ. Linn. Soc. Bot. Vol. xxix. 1893, pp. 333–346.
(An account of observations upon river drift in the Thames, Lea and Roding, with a discussion of the part played by birds in the dispersal of aquatic plants.)

 

 

 

 

 

24. Kerner, A. and Oliver, F. W. (1894–1895). The Natural History of Plants. 2 vols. , 1760pp., 1000 figs., 16 pls.
(This well-known book includes a good deal of information about water plants.)

 

 

 

 

 

25. Douval-Jouve, J. (1864). Lettre sur la découverte du Coleanthus subtilis en Bretagne. Bull. de la Soc. bot. de France, T. xi. 1864, pp. 265, 266.
(Notes on the part played by birds in the dispersal of aquatic plants.)

 

 

 

 

 

26. Guppy, H. B. (1894¹). Water Plants and their Ways. Science-Gossip, Vol. I. New Series, 1894. Their Dispersal and its Observation, pp. 145–147. Their Thermal Conditions, pp. 178–180. Ceratophyllum demersum, pp.195–199. 1 text-fig.
(These short papers, though published in a popular journal, contain original observations of great importance.) Guppy, H. B. (1897). On the Postponement of the Germination of the Seeds of Aquatic Plants. Proc. Roy. Phys. Soc. Edinburgh, Vol. XIII, 1894�. pp. 344–159.
(An account of experimental work on delayed germination of the seeds of water plants kept in water, with notes on the effect of drying, freezing and exposure to light or darkness.) Guppy, H. B.(1906). Observations of a Naturalist in the Pacific between 1896 and 1899. Vol II. Plant-dispersal. xxviii + 627 pp., I pl. London, 1906.
(The water-side plants of the British flora are considered in Chapters III and IV; Note 10, pp.535–538, records the degree of buoyancy of the seeds and seed vessels of more than 300 British plants, including a large number of aquatics. The book also contains numerous other notes on water plants, e.g. distribution of Naias, p. 367.)

 

 

 

 

 

27. Guppy, H. B. (1893). The River Thames as an Agent in Plant Dispersal. Journ. Linn. Soc. Bot. Vol. xxix. 1893, pp. 333–346.
(An account of observations upon river drift in the Thames, Lea and Roding, with a discussion of the part played by birds in the dispersal of aquatic plants.)

 

 

 

 

 

28. Ascherson, P. (1875). Die geographische Verbreitung der Seegrä:ser, in Dr G. von Neumayer's Anleiting zu wissenschaftlichen Beobachtungen auf Reisen, 1875, pp. 358–373 (also later editions).
(A detailed and suggestive account of the distribution of the marine members of the Potamogetonaceae and Hydrocharitaceae.)

 

 

 

 

 

29. Walsingham, Lord and Payne-Gallwey, R. (1886). Shooting (Moor and Marsh). Badminton Library. xiii + 348 pp. London, 1886.
(The authors mention, pp. 158 and 165, that Brent Geese feed on Zostera, and that these birds are almost confined to those parts of the coast where Zostera occurs.)

 

 

 

 

 

30. Areschoug, F. W. C. (1873²). On Trapa natans L., especially the form now living in the southernmost part of Sweden. Journ. Bot. Vol. XI. N. S. Vol. II. 1873, pp. 239–246, 1 pl.