Tibia of a mantophasmid insect (undescribed genus), showing the vibration-sensitive scolopidial organ. Stereo pair for convergent (cross-eyed) viewing. Bouin's/alcohol fixed, PTA-stained. It was necessary to cut segments of leg no longer than 3–4 mm to allow the PTA to penetrate through. Diameter of the leg is approx. 300 μm. This volume rendering shows the scolopidial organ, and individual sensory cells and fibers, muscle fibers, and single blood cells can be resolved clearly. Insect chitin stains more heavily with PTA than with iodine. Sample from Monika Eberhard, Univ. Vienna. Voxel size 0.9 μm.