Comparison of cartilage tube perichondrium calcification between two species of lizards. Cross-sections of mature regenerated tails of (A)
Anolis carolinensis and (B) the gecko Dactylocnemis pacificus analyzed by histology (von Kossa / Safranin O). Cartilage stains red, and calcified tissues stain black. The perichondrium of the Anolis cartilage tube calcifies, while the gecko cartilage tube resists calcification. ct, cartilage tube; pc, perichondrium; rsc, regenerated spinal cord. Bar = 50 μm.