Date of this Version
Recently, the habits and seasonal cycles of Australorbis glabratus and Tropicorbis centimetralis, intermediate hosts of Schistosoma mansonii, were studied intensively in the field in Brazil (Olivier and Barbosa, 1955a, b). In the course of these studies, the observations of Barbosa and Dobbin (1952) concerning the ability of A. glabratus to live out of water were confirmed and extended, and similar observations were made on T. centiwzetralis. In conjunction with these field studies, the snails were also studied in the laboratory where the environmental conditions were more constant and under a measure of control and where individual snails could be observed for long periods of time. Some of the experiments were designed to determine how long the two vector species could live out of water in the laboratory and whether there are strain differences within the species with respect to their ability to do this. In one group of such experiments, the snails were maintained without water in unglazed clay jars for long periods of time. The results of these experiments will be described here.