The human heart was stained by the modified PAS method (Otsuka and Hara method) and the distribution of Purkinje's fibers the subendocardium of the cardiac ventricle was reported. The Purkinje's fibers in subendocardium of the ventricular septum and the free region in humans are arranged as a network. On detailed investigation it was found that there were two areas that were mingled: One area that was macroscopically indistinguishable was found to have a fine and dense distribution. The other area was devoid of a distribution of the network. This distribution pattern resembles that of pigs but is unlike the morphology of other animals (monkeys, cows, goats, dogs, rabbits,rats and mice.
