In all study sites, algae were usually dead and more or
less degraded. Thus, our results are in accordance with
the observations of Mette et al. (2000) and Tschumpel
(2002) and contradict Cohn (1875), Hegner (1926),
Schumacher (1960) and Botta (1976). Probably, these
early authors failed to distinguish between active traps
and old, inactive or even dead ones. This may be
especially true for frequent observations of Euglena
living in the traps. Richards (2001) presents an image
of degraded Desmidiaceae inside a bladder of Utricularia
purpurea.