Russian physiologist (1849–1936) best known for his investigation of conditioned reflex through the use of experiments involving salivating dogs. He was awarded the Nobel Prize in Medicine in 1904. Large and bold fountain pen signature, “Prof. Dr. I. P. Pavlov,” on an off-white 5 x 2 trimmed card, in turn affixed to a 6 x 4 off-white album page. In fine condition, with a trivial spot below signature. RRAuction COA.