THE ANNALS 
MAGAZINE OF NATURAL HISTORY. 
[THIRD SERIES. } 
No. 120. DECEMBER 1867. 
<i: 
— 
XLVI.— Observations on the Aériferous Vesicles of the Utricu- 
larie. By 8. B. Scunerzier*. 
Tue genus Ufricularia consists of aquatic plants which we find 
in the stagnant waters of ditches, marshes, &c. The leaves are 
submerged, and divided into fine lacinize furnished with vesicles 
or utricles (asci). The following is the function ascribed by 
De Candolle to these organs. 
These utricles are rounded and furnished with a sort of move- 
able operculum. During the youth of the plant they are filled 
with a mucilage which is heavier than water; and the plant, 
held down by this ballast, remains at the bottom. Towards the 
period of flowering, the leaves secrete a gas which makes its way 
into the utricles, and drives out the mucilage by raising the 
operculum ; the plant, then furnished with a multitude of air- 
bladders, rises slowly, and at last floats at the surface. The 
flowering takes place in the open air; and as soon as it is com- 
pleted the leaves resume the secretion of mucilage, which re- 
places the air in the utricles; the plant again becomes heavier, 
and descends to the bottom of the water, in order to ripen the 
seeds in the very place where they have to be sownt. 
Notwithstanding the investigations of Goppert f, Benjamin § §, 
Schleiden ||, Schacht J, Reinsch **, &c., botanists have not yet 
arrived at a complete agreement as to the origin and morpho- 
* Translated by W.S. Dallas, F.L.S., from the ‘ Bibliothéque Univer- 
selle,’ tome xxix. August 25, 1867, pp. 296-311. 
Tt De Candolle, ‘ Physiologie végétale,’ tome ii. p. 87. 
+ Botanische Zeitung, 1847, p-/72l. Ihave not seen this work. 
§ Ibid. 1848, p. 17. 
|| Grundziige der wissenschaftlichen Botanik, 4th edit. p. 388. 
q Beitriige 2 zur Anatomie und Physiologie, 1854, p- 28. 
** Denkschriften der kén. Bayer. bot. “Geselisch. 1859, Bd. iv. p. 153 . 
(I ag not been able to procure this memoir); Reinsch, Das Mikroscop, 
1867 
Ann. & Mag. N. Hist. Ser. 3. Vol. xx. 27 
