Stage 4 of vitellogenesis and primary oocyte stage of oogenesis in C. metoecus. (9) A group of saturated lipid droplets, surrounded by glycogen granules, and a few shell globule clusters. Scale bar = 1 μm. (10) A part of the cytoplasm of a vitelline cell at the fourth stage of maturation. Note the abundance of glycogen granules around lipid droplets. Stained according to the Thiéry method. Scale bar = 1 μm. (11) Electron micrograph cross-section of ovary (arrowheads: basal lamina). Germ cells of the four stages of maturation are observed (I–IV). Scale bar = 2 μm. (12) Primary oocyte showing a small amount of cytoplasm, filled with free ribosomes, mitochondria, few granular endoplasmic reticula, and a chromatoid body. Scale bar = 1.5 μm. CB: chromatoid body; G: glycogen particle; GER: granular endoplasmic reticulum; L: lipid droplet; M: mitochondrion; N: nucleus; Nl: nucleolus; P: parenchyma; SGC: shell globule cluster.