Excerpt from Journal of Morphology, 1914, Vol. 25 The elaboration of other than the annelid theory of vertebrate ancestry upon which the orthodox conception has been largely based, has tended to throw doubt upon the View that the seg mentation of the vertebrate head is an ancestral segmentation. A morphologist of the last generation might have thought it necessary to apologize for advocating the View that the verte brate head is an unsegmented portion Of an unsegmented an cestor. N O apology would be required today. As a matter Of fact, after a century of vertebrate morphology, we actually do not know whether vertebrates came from a segmented or an unsegmented ancestor; whether or not the present segmentation in the head region is a true metamerism; whether the pre-otic portion Of the head is a coenogenetic addition to a primarily segmented body, or a palingenetic remnant of an unsegmented ancestor which has secondarily acquired a segmented trunk. Even among those who agree that the present segmentation is ancestral there is little accord as to the nature or number of these somites. 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.