Cuar. XVIII] STRUCTURE OF THE LEAVES. 361 
inch (705 mm.) in its longer diameter had a neck 1% of an 
inch (10°583 mm.) in length, and 11, of an inch (-254 mm.) 
in breadth. On each side of the orifice there is a long spiral 
arm or tube (a); the structure of which will be best under- 
stood by the following illustration. Take a narrow ribbon 
and wind it spirally round a thin 
cylinder, so that the edges come 
into contact along its whole 
length; then pinch up the two 
edges so as to form a little crest, 
which will of course wind spirally 
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 between 
them. They are indeed in many 
places a little separated, forming 
narrow entrances into the tube; 
but this may be the result of the 
drying of the specimens. The 
lamina of which the tube is 
formed seems to be a lateral pro- 
longation of the lip of the orifice ; 
and the spiral line between the 
two projecting edges is contin- 
uous with the corner of the orifice. 
If a fine bristle is pushed down 
one of the arms, it passes into Riéros 
he top of the hollow neck sok 
the top o e hollo eck. (Genlisea ornata.) 
Whether the arms are open Or  Utriculiferous leaf; enlarged about 
closed at their extremities could three times. 
not be determined, as all the | Upper part of lamina of leaf. 
specimens were broken; nor does =» Neck of utricle. 
It appear that Dr. Warming a Spinaily wound arms, with their 
ascertained this point. ends broken off. 
So much for the external struc- 
ture. Internally the lower part of the utricle is covered with 
spherical papille, formed of four cells (sometimes .eight 
according to Dr. Warming), which evidently answer to the 
quadrifid processes within the bladders of Utricularia. These 
