Fig. 3

X-cells from rainbow trout kidney. a, b Squash preparations, showing x-cells (arrows) filled with refractive granules (a brightfield, b interference contrast). c–f X-cells in Hemacolor-stained kidney imprints. Note multiple nuclei and vacuolate cytoplasm; methanol fixation removed the refractive granules. Scale bar (a–f): 20 μm