ABSTRACT
Extraction and quantitative determination of progesterone, testosterone and oestrogens have been made in tissues of cephalopod molluscs and crustaceans. Extraction was made by acetone and ethyl ether. Purification was performed by thin layer chromatography on aluminium oxide and silicagel in different systems. The quantitative assay of progesterone and oestrogens was made by fluorimetric and radioimmunological techniques, that of testosterone--by spectrophotometric determination of hydrozones and radioimmunological procedure. Progesterone and testosterone were obtained from the gonads and liver of cephalopods and from the whole body of crustaceans. During sexual maturation of the animals concentration of these hormones tends to increase. Oestrone and oestradiol were found only in the gonads of cephalopods.