Download or read book Contributions From the Zoological Laboratory of the University of Pennsylvania, Vol. 1 (Classic Reprint) written by UNKNOWN. AUTHOR and published by Forgotten Books. This book was released on 2015-07-27 with total page 116 pages. Available in PDF, EPUB and Kindle. Book excerpt: Excerpt from Contributions From the Zoological Laboratory of the University of Pennsylvania, Vol. 1 1. It was long ago pointed out by Herbert Spencer, and before him by Leuckart, that, as organized unicellular bodies increase in bulk, their surfaces become proportionally less; and that this elementary rule of growth very probably leads to the necessity for segmentation or sub-division of the original cellular body, owing to the unfavorable conditions which continuous growth establishes between the organism and its surroundings, because of the more rapid increase of volume than of surface, thus developing unfavorable conditions for nutrition, respiration, and consequently, for metabolism and growth in general. It was assumed that the dimensions of the cellular body are in some way self-regulated, and that segmentation or cell-division is a method automatically resorted to during the growth of multicellular organisms, by means of which they are enabled to continually recur to more favorable conditions in respect to the ratios between the volumes and surfaces of their constituent cells. 2. The law of change of the ratios between volumes and surfaces of cells can be most clearly illustrated by two parallel series of numbers, showing the simultaneous increase of volumes and surfaces of a series of cubes whose sides increase at an integral rate, or by a difference of one; that is, a series of cubes whose edges measure 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, etc., taken consecutively. The first of the two parallel series may represent the surfaces of such a series of cubes, and is as follows: 6, 24, 54, 96, 150, 216, 294, 384, 486, 600. 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.