Chap. XIV.] ALDROVANDA VESICULOSA. 261 



CHAPTER XIV. 



ALDROVANDA VESICULOSA. 



Captnres crustaceans Structure of the leaves in comparison with those of 

 DioDsea Absorption by the glands, by the quadrifid processes, and 

 points on the infolded margins Ahlrovanda vesiculosa, var. australis 

 Captures prey Absorption of animal matter Aldrovanda vesiculosa, 

 var. vertukllata Concluding remarlis. 



This plant may be called a miniature aquatic Dionsea. 

 Stein discovered in 1873 that the bilobed leaves, which are 

 generally found closed in Europe, open under a suflBciently 

 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 con- 

 tain bubbles of air, and were formerly supposed to be blad- 

 ders; 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 grow- 

 ing plants many kinds of crustaceans and larvae.' Plants 

 which have been kept in filtered water were placed by him 

 in a vessel containing numerous crustaceans of the genua 

 Cypris, and next morning many were found imprisoned and 

 alive, still swimming about within the closed leaves, but 

 doomed to certain death. 



Directly after reading Prof. Cohn's memoir, I received 

 through the kindness of Dr. Hooker living plants from 



Since his original pubiicatlon, [The late Professor Caspary 



Stein has found out that the Ir- published in the ' Bot. Zeituug,' 



rltability of the leaves was ob- 1859, p. 117, an elaborate paper 



served by De Snssus, as recorded on Aldrovanda, dealing chiefly 



In ' Bull. Bot. Soc. de France,' in with its morphology, anatomy, 



1W51. Dolpino states in a paper systematic position and geo- 



published In 1871 (' Nuovo Glor- graphical distribution. The early 



nale Bot. Ital.' vol. III. p. 174) literature of the species Is also 



that "una quantity dl chiocoioline fully given. F. D.] 



e dl altrt nnlmalcoll aoqnatioi " ' I am greatly Indebted to this 



are caught and suflfocated l)y the distinguished naturalist for hav- 



leaves. I presume that chiocrio- Ing sent m> a copy of his memoir 



line are fresh-water molluscs. on Aldrovanda. before it.s piildi- 



It would be interesting to know cation in his ' Beitrilge sur Hlolo- 



whether their shells are at all gie dor I'flanzeu,' drittea Ileft. 



corr<Mled' by the acid of the dl- 1875, p. 71. 

 gestlve secretion. 



