The nucleoli and cytoplasm of the eggs of several marine animals were studied, including Asterias, Mactra, Chaetopterus and Arbacia. In living eggs the nucleolus is generally in 2 parts, the outer one being more soluble in fresh water than the inner globule (nucleolinus). Tests for lipoids in the nucleoli gave negative results. When living eggs are treated with Schiff''s reagent, without hydrolysis, the cytoplasm quickly or slowly turns magenta, probably owing to acetalphos-phatids present. In crushed eggs of Chaetopterus the cytoplasmic granules, which are of various sizes, are colored magenta to different degrees, some granules remaining unstained while the smallest granules stain most intensely. The aldehyde substance concerned is soluble in alcohol. There was no evidence of phospholipids in the nucleolus. Eggs and oogonia of Fucus do not give the Feulgen reaction without hydrolysis, but if subsequently exposed to air the thallus turns purple. On heating in Feulgen, the eggs and the colorless medullary strands turn pink and magenta bodies appear in the medullary strands.