Fig. 3. Sections of the opaque-white region of the prosoma of a white spider. (A) Unstained section showing the granules filling the epidermal cells (bar, 30 µm). (B) Same region of tegument as in A, observed under UV light. The granules are strongly autofluorescent (bar, 10 µm). (C) Same region as A and B, observed through a linear polarizer. Numerous granules appear as brilliant (birefringent) against the dark background (bar, 20 µm). (D) Electron micrograph of the epidermal cells of the same region, showing the granules full of microcrystal inclusions (arrow) (bar, 1 µm). C, cuticle; E, epidermis; N, nucleus.