VENUS' S FLY-TRAP. 67 



With this brief and rapid summary of the main 

 features relating to the carnivorous propensities of 

 the Vcnus's Fly-trap, we may casually refer to a few 

 other plants belonging to the same natural order as 

 the Sundews and Dionoea, which possess similar 

 propensities, but to a less interesting degree, or do 

 not differ greatly from the two preceding types. 



A little aquatic plant, called Aldrovanda vesiculosa 

 is found in Europe, Australia, and India. Although 

 inhabiting countries so remote from each other, this 

 plant seems to be of one species in all. It has no 

 roots, and floats like green stars in the water. The 

 leaves are arranged in whorls in a stellate manner 

 round the stem. Each leaf has two semicircular lobes, 

 which are seated on broad foot-stalks. The lobes 

 are generally found closed at the ordinary tempera- 

 ture in Europe, but they do separate, under favour- 

 able conditions, to about the same proportionate 

 extent as a living mussel opens the valves of its shell. 



The history and mystery of this little water-plant 

 are very imperfectly known. Stein observed that water 

 insects v/ere sometimes caught by it. Professor Cohn 

 has found crustaceans and larva; within the leaves.^ 

 Plants placed in water containing entomostraca were 

 examined next morning, and found to enclose indi- 

 viduals of these minute crustaceans still alive. In 



1 Cohn, "Beitrage,"' iii., 1875, P- 7^- 

 F 2 



