THE INTERRELATIONS OF PROTOZOA AND THE UTRICLES OF UTRICULARIA

Abstract

Livingspedmens of Sarcodina, Mastigophora, and Infusoria were found in bladders in nature. Protozoa do not force their way in but the bladders expand when properly stimulated and the Protozoa are sucked in. Any organism that properly stimulates the bladder may be captured, i.e., the bladder does not select its prey. Protozoa may live successfully within (Euglena, Heteronema, Phacus), starve to death (Centropyxis), or are more or less quickly killed and digested (Paramecium, Stentor, Stylonychia, Colpidium) Experiments indicate that the bladders secrete something that kills and digests Paramecium but does not injure Euglena. The protozoa are not intruders, but captives and are probably free-living species.