Cuap. X1V. ALDROVANDA VESICULOSA. 321 
CHAPTER XIV. 
ALDROVANDA VESICULOSA. 
Captures crustaceans — Structure of the leaves in comparison with 
those of Dionza — Absorption by the glands, by the quadrifid pro- 
cesses, and points on the infolded margins — Aldrovanda vesiculosa, 
var. australis— Captures prey — Absorption of animal matter — 
Aldrovanda vesiculosa, var. verticillata — Concluding remarks. 
’ 
Tuis plant may be called a miniature aquatic Dionza. 
Stein discovered in 1878 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 inor- 
ganic 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 larve.t Plants which had been kept 
in filtered water were placed by him in a vessel con- 
* Since his original publication, 
Stein has found out that the irri- 
tability 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 Gior- 
nale Bot. Ital.’ vol. iii. p. 174) 
that “una quantita di chioccio- 
line e di altri animalcoli acqua- 
tici” are caught and suffocated 
by the leaves. I presume that 
chioccioline are fresh-water mol- 
luscs. It would be interesting to 
know whether their shells are at 
all corroded by the acid of the 
digestive secretion. 
+ Iam greatly indebted to this 
distinguished naturalist for having 
sent me a copy of his memoir on 
Aldrovanda, before its publica- 
tion in his ‘ Beitrage zur Biologie 
der Pflanzen,’ drittes Heft, 1875, 
p. 71. 
