Excerpt from Johns Hopkins University Circulars, Vol. 9: April, 1890 The separate sense organs of' the lateral line are formed in the following way. The elongated sac constricts and is divided into two parts, of which the anterior is the smaller. The two portions separate, remaining connected for some little while by a strand of cells which subsequently disappears. The anterior sac runs through the same series of changes described for the branchial sense organ. Its cavity is flattened out, histological modification sets in, and it becomes a segmental sense organ, situated in the anterior part of the trunk. The posterior sac shortly after divides in the same way, the anterior portion becoming a sense organ in front of the anus. The posterior portion, by the time the division is over, has lost the character of a sac and is a mere cord of cells, lying behind the anus. On this. Cord on one, and in some cases on two spots, sense organs are found in process of forming. This is the condition at the time of hatching. Prof. Whitman, in a recent paper states he is satisfied that it is not by division that the lateral line organs increase in number. How the increase takes place after hatching I do net know. From the character of the sensory tract in the tail of the just-hatched bass, I should think it probably was effected by local proliferation along a continuously growing linear tract of sensory cells. But before hatching the increase unquestion ably takes place by division. 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.