Many nucleolar buds have been observed in the nucleus of the early oocytes of Clibanarius. Some of them are extruded in the cytoplasm through the nuclear membrane. They fragment into fine granules containing ribonucleoproteins. There is a decrease in pyroninophilia in the ooplasm with the advent of appearance of compound yolk. RNA present in nucleolar extrusions is utilised in protein yolk synthesis. Nucleolus and nucleolar extrusions contain proteins (-NH and -SH groups; and tyrosine), RNA and lipoproteins.