Light micrograph of a normal cortex at the surface of a kidney. The cortex contains glomeruli (larger circular structures) as well as tubules (red smaller circular or elongated structures around the glomeruli). The surface of the kidney is lined by a capsule (thick blue curvilinear line at the top). Some interstitial fibrosis can also be seen, consisting of the blue staining areas beneath the capsule and in between the tubules. Trichrome stained tissue section. Magnification: x40 when printed at 10cm wide.