"In the numerous observations made in my laboratory upon this object, we have only once seen a combination of vessels in which there might be a direct communication between a small artery and a vein, though the two observers could not come to a final conclusion on the point."
August Krogh was a Danish physiologist who won the 1920 Nobel Prize in Physiology or Medicine for his work on capillary regulation in skeletal muscle. He made foundational contributions to respiratory and comparative physiology.