Printed in Great Britain EXCRETION IN THE CEPHALOPOD, OCTOPUS DOFLEINI

Although excretory processes in vertebrate animals have been studied extensively during the past fifty years, comparatively few investigations have been carried out on invertebrates. The cephalopod molluscs represent a group which is suited to experi-mental study due to the large size that has been attained by some of the forms, their relatively high and constant level of metabolic activity and the presence of excretory structures which are accessible and well defined. For these reasons a study was initiated on the large octopus of Puget Sound, Octopus dofleim martini (Pickford, 1964). Previous studies of the excretory system of the octopus have been limited for the most part to morphological investigations. The majority of these have been reviewed by Turchini (1923). The early physiological experiments conducted by Solger (1881), Kovalevsky (1889) and Cuenot (1899) consisted of injections of dye solutions with subsequent observations of the areas of localization. These authors reported dye accumulation in the renal appendages, the branchial hearts and the branchial heart appendages. From these results they considered these to be. sites of excretion in the octopus