133 FREAKS OF PLANT LIFE. 



{Utriciilaria neglecta and Utriailaria vulgar is), f[g. 19. 



These are aquatic, commonl}- found in dirty ditches-, 



or, as has been said, " remarkably foul ditches." They 



float freely, not being attached by roots at any period 



of their existence. The leaves are deeply divided 



into narrow filaments, each terminating in a short 



straight point, like a bristle. Small inflated vesicles,. 



or bladders, seated on the leaves, originated the name 



of bladderwort. It is sometimes stated that these 



bladders are filled with air, and serve 



to buoy up the plant in the water. 



That such an assertion is erroneous 



may be inferred from the fact that 



although they often enclose a little 



bubble of air, they are usually filled 



r^. ,,, ,j with water ; that branches float 



Fig. 20. — Bladder 



oiUtricitlariavul- equally well without them ; and that 

 garis, enlarged. their elaborate construction indicates 

 a much more complex function, what- 

 ever that function may be. 



The chief point of interest is offered by these 

 bladders, the minute structure of which is exhaustively 

 treated in Mr. Darwin's work, but our purpose may 

 be served by a meagre outline. When full grown the 

 bladders arc nearly one-tenth of an inch in length, 

 nearly egg-shaped (fig. 20) with the smaller end up- 

 wards, and attached obliquely towards the base. The 

 upper, or smaller, end is furnished with si.v or se\en 



