[.18.] 
VI. Preliminary Note on the rate of Growth of the Female Flower-stalk of Vallisneria 
spiralis, Linn. Ву AvrnED W. BENNETT, M.A., B.Sc., F..L.S., Lecturer on Botany 
at St. Thomas’s Hospital. 
Read November 4th, 1875. 
ALTHOUGH the extraordinary rapidity of growth of the peduncle of the female flower 
of Vallisneria spiralis (probably one of the most remarkable instances to be found in the 
vegetable kingdom) appears to be familiar to botanists, I have been unable to find 
any record of actual measurements. Тһе present communication to the Society I prefer 
to call a “ Preliminary Note,” inasmuch as a much more extensive series of experiments 
than I have at present had the opportunity of making will be required before the subject 
can be considered exhausted. 
The object of the great length attained by the female flower-stalk is well known. The 
flower is by this means brought to the surface of the water in which it grows, which 
I should infer, from the length it attains (though I do not recollect any exact record 
of this), to be from three to four feet. It is there fertilized by the pollen supplied by the 
male flower, which, growing submerged on a short peduncle, breaks off from it and rises 
to the surface, where it floats about until the pollen meets with a female flower, the 
latter after impregnation being again carried, by the spiral coiling of the peduncle, 
beneath the surface, where it ripens its seeds. 
The first memoir, as far as I have been able to trace, of the structure of Vallisneria is 
by Е. J. Quekett, ** Observations connected with the Anatomy and Physiology of Vallis- 
neria spiralis," in the first and only volume of the * London Physiological Journal’ for 
1843. Тһе mode of fertilization and the phenomena of rotation within the cells of the 
leaves are here described; and the description appears to be the basis of the ordinary 
accounts found in works on descriptive botany. А far more minute and accurate 
account of the structure of the plant is by Chatin, in his ‘ Mémoire sur le Vallisneria 
spiralis, Linn., considéré dans son organographie, sa végétation, son organogénie, son 
anatomie, sa tératologie, et sa physiologie, 1855. "The author of this memoir points out 
the singular error into which previous writers have fallen, in describing the peduncle of 
the female flower as originally coiled up spirally and unrolling towards the period of 
impregnation, an error repeated by Richard, Turpin, and even by Grenier and Godron in 
their * Flore de France, and by nearly all subsequent writers, whether scientific or 
popular, and forming the text of one of Erasmus Darwin's most роейса] images in his 
“ Loves of the Flowers. Chatin states, and with perfect correctness, that “la hampe 
des fleurs femelles, d'abord droite, ne se déroule jamais." Neither of these authors, 
however, gives any details on the special subject of this paper. 
The first flower noticed on the plants growing in my aquarium, where the water is 
about 8 inches deep, was on July 19th of the present year, when the total length of the 
