Onap. XVII.] STRUCTURE OF THE BLADDER. 323 
those (four in number) on the near side are shown in the 
drawing. These bristles, together with those borne by the 
antenns, form a sort of hollow cone surrounding the 
entrance. 
The valve slopesinto the cavity of the bladder, or upwards 
in fig. 18. It is attached on all sides to the bladder, 
excepting by its posterior margin, or the lower one in fig. 
19, which is free, and forms one side of the slit-like orifice 
leading into the bladder. This margin is sharp, thin, and 
smooth, and rests on the edge of a rim or collar, which dips 
deeply into the bladder, as shown in the longitudinal section 
(fig. 20) of the collar and valve; it is also shown atc, in 
g. 18. The edgo of the valve can thus open only inwards. 
Fie, 20, 
(Utricularia neglecta.) 
Longitudinal vertical section through the ventral portion of a bladder; showing valve and 
collar. v, valve; the whole projection above c forms the collar; b, bifid processes; 3, 
ventral surface of bladder, 
As both the valve and collar dip into the bladder, a hollow 
or depression is here formed, at the base of which lies the 
slit-like orifice. 
The valve is colourless, highly transparent, flexible and 
elastic. It is convex in a transverse direction, but has been 
drawn (fig. 19) in a flattened state, by which its apparent 
breadth is increased. It is formed, according to Cohn, of two 
layers of small cells, which are continuous with the two 
layers of larger cells forming the walls of the bladder, of 
which it is evidently a prolongation. Two pairs of trans- 
parent pointed bristles, about as long as the valve itself, 
arise from near the free posterior margin (fig. 19), and point 
obliquely outwards in the direction of the antennw. There 
y 2 
