Figure 1. Vitellogenin staining of a stage 1, previtellogenic non-activated ovary. The low magnification micrograph (5 x) of ovarioles (a), consists of undeveloped cells in the anterior end and more developed oogonia (o) and trophocytes (t) (nurse cells) in the posterior end. Cross sections (bright field: b and dark field b’) and longitudinal sections (bright field: c and dark field: c’) at a primary magnification of 40 x; show oogonia and developing multinuclear trophocytes. The ovary shows no positive staining for vitellogenin (a-c). Positive staining is shown in Figures 2–6.