Excerpt from The Johns Hopkins Hospital Reports, 1920, Vol. 19 We have then two perfectly fresh hearts belonging to men of practically the same age, the one pathological and the other normal. We propose here to set forth all the observations which we have been able to make upon this valuable material. It would have been interesting, had it been possible, to study the evolution of the fibers of Purkinje from the earliest embryonic stages up to the age of 70 to 80 years, but at present we have not the necessary material. Nevertheless we are able to present certain new facts in the morphological study of the fibers of Purkinje in the adult. These facts also permit us to evaluate correctly the pathological alterations in the diseased specimen. About the Publisher Forgotten Books publishes hundreds of thousands of rare and classic books. Find more at www.forgottenbooks.com This book is a reproduction of an important historical work. Forgotten Books uses state-of-the-art technology to digitally reconstruct the work, preserving the original format whilst repairing imperfections present in the aged copy. In rare cases, an imperfection in the original, such as a blemish or missing page, may be replicated in our edition. We do, however, repair the vast majority of imperfections successfully; any imperfections that remain are intentionally left to preserve the state of such historical works.