260 ALDROVANDA VESICULOSA. (CHar. XIV. 
CHAPTER XIV. 
ALDROVANDA VESICULOSA. 
Captures erustaceans—Structure of the leaves in comparison with those of 
Dionza—Absorption by the glands, by the quadrifid processes, and points 
on the infolded margins—Aldrovanda vesiculosa, var. australis—Captures 
prey—Absorption of animal matter—A/drovanda vesiculosa, var. verticillata 
—Concluding remarks. 
Tuts plant may be called a miniature aquatic Dionæa. Stein 
discovered in 1873 that the bilobed leaves, which are 
generally found closed in Europe, open under a sufficiently 
high temperature, and, when touched, suddenly close.* 
They re-expand in from 24 to 36 hrs., but only, as it appears, 
when inorganic objects are enclosed. The leaves sometimes 
contain bubbles of air, and were formerly supposed to be 
bladders; hence the specific name of vesiculosa. Stein 
observed that water-insects were sometimes caught, and 
Prof. Cohn has recently found within the leaves of naturally 
growing plants many kinds of crustaceans and larvæ.f 
Plants which have been kept in filtered water were placed 
by him in a vessel containing numerous crustaceans of the 
genus Cypris, and next morning many were found imprisoned 
and alive, still swimming about within the closed leaves, 
but doomed to certain death. 
* Since his original publication, 
alec nan 
Stein has found out that the irrita- 
bility of the leaves was observed by 
De Sassus, as recorded in * Bull. Bot. 
Soc. de France,’ in 1861. Delpino 
states in a paper published in 1871 
(‘Nuovo Giornale Bot. Ital.’ vol. iii. 
p- 174) that “una quantita di chioc- 
cioline e di altri animalcoli acquatici ” 
are caught and suffocated by the 
leaves. I presume that chioccioline 
are fresh-water molluscs. It would 
be interesting to know whether their 
shells are at all corroded by the acid 
of the digestive secretion. | 
[The late Professor Caspary pub- 
lished in the ‘Bot. Zeitung,’ 1859, 
p. 117, an elaborate paper on Aldro- 
vanda, dealing chiefly with its morpho- 
logy, anatomy, systematic position 
and geographical distribution. The 
early literature of the species is also 
fully given.—F. D. 
t+ I am greatly indebted to this 
distinguished naturalist for having 
sent me a copy of his memoir on 
Aldrovanda, before its publication in 
his ‘ Beiträge zur Biologie der Pflan- 
zen,’ drittes Heft, 1875, p. 71. 
