Sandwich cultures of sponges provide a convenient means to study a sponge's internal organization and the physiological activities of sponge cells. In this study, the feasibility of using sponge explants as a source for sponge tissue in sandwich cultures was evaluated and the organization of the sponge's canal system was observed. Explants from Eohydatia muelleri. obtained from Salmon Lake, were attached to sandwich culture assemblies. Cells were allowed to grow out from the explants between closely spaced glass slides. Culturing was carried out either in Salmon Lake or in the laboratory for two to three weeks. Although there was little outgrowth in the laboratory, in the lake, tissue spread approximately 1.5cm from the sponge explant. Flagellated chambers were visible in the sponge tissue between the glass slides; however, connections between them were not. A model for the development of flagellated chambers is proposed.