Light micrograph of the renal cortex. The presence of renal corpuscles stands out, and the Bowman's space (white space) around the glomerular vascular tuft can be clearly distinguished. The space between the glomeruli is occupied by sections of convoluted tubes. Crossing the image obliquely are two groups of tubules sectioned longitudinally. They are the medullary rays, also called columns or Ferrein's pyramids. They contain collecting ducts and straight portions of the proximal and distal convoluted tubules. The vessels in the lower right corner are an arcuate artery and vein.