The Development of the Ovary and Oviduct of the Gold Fish

Sex differentiation in the gold fish begins in embryos of about 14 to 16 mm. in length. In the female the germ cells increase rapidly in size and have a tendency to become arranged in rows. A distinct central nucleolus is not present, but round nucleolar bodies are arranged peripherally against the nuclear membrane. These bodies seem to give off buds which pass through the nuclear membrane into the cytoplasm. During the early stages the cytoplasm becomes basophilic. In very young oocytes this is limited to a narrow zone immediately surrounding the nucleus. It then spreads peripherally until the entire cytoplasm stains deeply with basic stains. When yolk formation begins the cytoplasm changes back to the acidophilic condition again