The localization of Cl− in the digestive glands of Dionaea muscipula Ellis (Venus's Flytrap) was studied by the AgCl precipitation technique. From these studies, the digestive cycle of Dionaea is considered to comprise two phases: a preparatory and a secretory phase. During the preparatory phase which ensues within 15 min of the start of stimulation, only the head cells of the gland accumulate Cl−. After about 5 h of stimulation, the vacuoles of the head cells appear to have undergone fragmentation. During the succeeding 2 h the head cells lose most of their Cl− accumulations and, at about the same time, Cl− appears in their outer walls. During the secretory phase, the onset of which can only be demonstrated after about 17 h of stimulation, Cl− can be seen in the endodermoid and basal cells of the digestive glands. At the end of the digestive cycle and during the time between the first and subsequent cycles only the basal cells show large amounts of Cl−.
The Cl− that is redistributed is shown to be of endogenous origin and the results are discussed with respect to the functional anatomy of the gland complex.