Abstract
1. The present studies deal with the histochernical observation on nucleolus and its extrusions in the egg-follicle of five dipteran species, viz., Dyosophila melanogaster, Musca domestica, Dacus cucuybitae, Psychoda bengalensis and Culex fatigans.
2. The trophocyte and oocyte nucleolus consists of RNA, proteins and bound lipids, except in Dyosophila and Musca; in these species the oocyte nucleolus does not possess RNA.
3. DNA appears in the oocyte nucleolus during the growth period in all the five species.
4. The nucleolus buds off granules rich in ribonucleoporteins and bound lipids; these granules migrate into the ooplasm.
5. The mode of emission of the nucleolar material and their role in proteid yolk synthesis have been discussed.
