Cuar. XVIII. STRUCTURE OF THE LEAVES. 447 
round the cylinder like a thread round a screw. If the 
cylinder is now removed, we shall have a tube like one 
of the spiral arms. The two projecting edges are not 
actually united, and a needle 
can be pushed in easily be- 
tween them. They are in- 
deed in many places a little 
separated, forming narrow 
entrances into the tube; 
but this may be the result 
of the drying of the speci- 
mens. The lamina of which 
the tube is formed seems 
to be a lateral prolongation 
of the lip of the orifice; 
and the spiral line between 
the two projecting edges is 
continuous with the corner 
of the orifice. If a fine 
bristle is pushed down one 
of the arms, it passes into 
the top of the hollow neck. 
Whether the arms are open 
or closed at their extre- 
mities could not be deter- Fic. 29. 
: : (Genlisea ornata.) 
mined, as all the apecimens Utriculiferous leaf; enlarged about 
were broken; nor does it three times, 
Upper part of lamina of leaf. 
ricle or bladder. 
Neck of utricle. 
appear that Dr. Warming 
ascertained this point. Orifice. 
So much for the external aN eed meena, veh bine 
structure. Internally the 
lower part of the utricle is covered with spherical 
papille, formed of four cells (sometimes eight accord- 
ing to Dr. Warming), which evidently answer to the 
quadrifid processes within the bladders of Utricularia, 
acsan 
