xii LIST OF ILLUSTRATIONS 



FIG. PAGE 



30. Hydrocharis Morsus-ranae, L. Turion plantlet. [A. A.] . . 49 



31. Stratiotes aloides, L. Stem bisected. [Arber, A. (1914)] . . 49 



32. Stratiotes aloides, L. Habit drawing. [Nolte, E. F. (1825)] . . 53 



33. Stratiotes aloides, L. Female flower. [A. A.] .... 54 



34. Elodea canadensis, Michx. Wintering shoot. [Raunkiaer, C. (1896)] 55 



35. Elodea ioensis, Wylie. Male flowers. [Wylie, R. B. (1912)] . . 56 



36. Potamogeton perfoliatus, L. Winter shoots. [A. A.] ... 59 



37. Potamogeton. Branch system. [Sauvageau, C. (1894)] ... 60 



38. Potamogeton zosterifolius, Schum. Vascular strands and bast bundles 



of leaf. [Raunkiaer, C. (1903)] 6l 



39. Potamogeton pulcher, Tuckerm., P. natans, L. and P. crispus, L.; 



stem-stele. [Chrysler, M. A. (1907)] 62 



40. Potamogeton crispus, L., P. lucens, L., P. pusillus, L., P. pectinatus, 



L. ; stem-stele. [Schenck, H. (1886)] 64 



41. Potamogeton natans, L., P. densus, L., P. pectinatus, L.; root 



anatomy. [Schenck, H. (1886)] 65 



42. Potamogeton crispus, L. Germinating turion. [A. A.] ... 67 



43. Potamogeton crispus, L. Germinated turion at advanced stage. 



[Sauvageau, C. (1894)] 68 



44. Potamogeton rufescens, Schrad. T. S. turion. [Gluck, H. (1906)] . 69 



45. Zannicbellia polycarpa, Nolte. Flowers. [A. A.] .... 70 



46. Potamogeton perfoliatus, L. Fruit wall. [A. A.] .... 72 



47. Spirodela polyrrbiza, Schleid. Inflorescence. [Hegelmaier, F. (1871)] 74 



48. Lemna gibba, L. [Hegelmaier, F. (1868)] 76 



49. Lemna trisulca, L. [Kirchner, O. von, Loew, E. and Schroter, C. 



(1908, etc.)] 79 



50. Lemna trisulca, L. Flowering shoot. [Hegelmaier, F. (1868)] . 79 



51. Lemna trisulca, L. T. S. bundle from stalk of frond. [Schenck, H. 



(1886)] 79 



52. Lemna trisulca, L. Germination. [Hegelmaier, F. (1868)] . . 81 



53. Pistia Stratiotes, L. Leaf apex. [Minden, M. von (1899)] 82 



54. Ceratophyllum demersum, L. Flowers. [A. A.] .... 85 



55. Ceratophyllum demersum, L. Seedling. [Guppy, H. B. (1894!)] . 86 



56. Ceratophyllum demersum, L. Stem-stele. [Schenck, H. (1886)] . 87 



57. Ceratophyllum demersum, L. Rhizoid. [Gluck, H. (1906)] . . 89 



58. Ceratophyllum demersum, L. Leaves of water shoot and rhizoid. 



[Gluck, H. (1906)] 89 



59. Utricularia neglecta, Lehm. Leaf with bladders. [Gluck, H. (1906)] 92 



60. Utricularia fiexuosa, Vahl. Section through bladder. [Goebel K 



(1891-1893)] 02 



61. Utricularia Bremii, Heer. Glands from bladder. [Meierhofer, H. 



93 



