Cuar. XVIL STRUCTURE OF THE BLADDER. 403 
tremely thin transparent membrane, so that they can 
be bent or doubled in any direction without being 
broken. They are lined with a delicate layer of proto- 
plasm, as is likewise the short conical projection from 
which they arise. Hach arm generally (but not in- 
variably) contains a minute, faintly brown particle, 
either rounded or more commonly elongated, which 
exhibits incessant Brownian movements. These par- 
Fie. 21. 
(Utricularia neglecta.) ee 22, 
Small portion of inside of blad- (Utricularia neylecta.) 
der, much enlarged, showing quad- One of the quadrifid processes 
rifid processes. greatly enlarged. 
ticles slowly change their positions, and travel from 
one end to the other of the arms, but are commonly 
found near their bases. They are present in the quad- 
rifids of young bladders, when only about a third of 
their full size. They do not resemble ordinary nuclei, 
but I believe that they are nuclei in a modified con- 
dition, for when absent, I could occasionally just dis- 
tinguish in their places a delicate halo of matter, 
including a darker spot. Moreover, the quadrifids of 
Utricularia montana contain rather larger and much 
