Excerpt from The Protoplasm Theory: An Introductory Lecture Delivered at the Opening of the Winter Session of the College of Physicians and Surgeons, New York, October, 1, 1873With respect, finally, to the methods by which protoplasm performs the fundamental vital acts, I need not recapitulate what has been so often described already. I will only in this connection point out to you the important fact that so far as observation has yet gone - mark the proviso-protoplasm has never been definitely known to arise de novo, but is always found derived from pre-existing protoplasm by bodily division of one unit-mass into new individuals or germs.Such, then, are the pregnant facts that the microscope has re vealed, and I leave you to judge whether I was justified in say ing at' the beginning of the lecture that a common denominator of life had been found. You have seen that throughout the vast domain of the animate world, from man to the monera, there is but one kind of actively living matter - protoplasm but one mode of its existence, in elementary unit-masses: but one scheme of tissue-building, the multiplication and transformation of such elements: and apparently but one mode of continuance of life on earth, direct division of protoplasm-units into new genera tions of the same.About the PublisherForgotten Books publishes hundreds of thousands of rare and classic books. Find more at www.forgottenbooks.comThis 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.