This work has been selected by scholars as being culturally important, and is part of the knowledge base of civilization as we know it. This work was reproduced from the original artifact, and remains as true to the original work as possible. Therefore, you will see the original copyright references, library stamps (as most of these works have been housed in our most important libraries around the world), and other notations in the work. This work is in the public domain in the United States of America, and possibly other nations. Within the United States, you may freely copy and distribute this work, as no entity (individual or corporate) has a copyright on the body of the work. As a reproduction of a historical artifact, this work may contain missing or blurred pages, poor pictures, errant marks, etc. Scholars believe, and we concur, that this work is important enough to be preserved, reproduced, and made generally available to the public. We appreciate your support of the preservation process, and thank you for being an important part of keeping this knowledge alive and relevant.

Excerpt from Illinois Biological Monographs, Vol. 3 The precautions taken to meet the demands of the experiments are not discussed in detail because they have already been given in previous papers. The frog tadpoles (when they can be used) are in all respects more suitable than salamander larvae. When collected late in the fall they can be kept at a fairly constant size and the results obtained under these conditions are not complicated with growth phenomena. They have proved to be remarkably uniform in several series. The salamander larvae on the other hand vary in rate of regeneration from day to day. The factors involved in this fluctuation were not discovered and could not be remedied but may be related in some way to the fact that these animals require living active food and the feeding reactions are therefore more complicated than in frog tadpoles and more subject to disturbance. In regard to certain factors, such as the degree of injury, in which expected differences in rate are slight the writer has felt that he might be biased in making the measurements and in a number of cases this work was therefore delegated to a person who had no preconceptions concerning the result. 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.

This work has been selected by scholars as being culturally important, and is part of the knowledge base of civilization as we know it. This work was reproduced from the original artifact, and remains as true to the original work as possible. Therefore, you will see the original copyright references, library stamps (as most of these works have been housed in our most important libraries around the world), and other notations in the work. This work is in the public domain in the United States of America, and possibly other nations. Within the United States, you may freely copy and distribute this work, as no entity (individual or corporate) has a copyright on the body of the work.As a reproduction of a historical artifact, this work may contain missing or blurred pages, poor pictures, errant marks, etc. Scholars believe, and we concur, that this work is important enough to be preserved, reproduced, and made generally available to the public. We appreciate your support of the preservation process, and thank you for being an important part of keeping this knowledge alive and relevant.

This work has been selected by scholars as being culturally important, and is part of the knowledge base of civilization as we know it. This work was reproduced from the original artifact, and remains as true to the original work as possible. Therefore, you will see the original copyright references, library stamps (as most of these works have been housed in our most important libraries around the world), and other notations in the work. This work is in the public domain in the United States of America, and possibly other nations. Within the United States, you may freely copy and distribute this work, as no entity (individual or corporate) has a copyright on the body of the work.As a reproduction of a historical artifact, this work may contain missing or blurred pages, poor pictures, errant marks, etc. Scholars believe, and we concur, that this work is important enough to be preserved, reproduced, and made generally available to the public. We appreciate your support of the preservation process, and thank you for being an important part of keeping this knowledge alive and relevant.

Excerpt from Illinois Biological Monographs, Vol. 3: Studies on the Factors Controlling the Rate of Regeneration, August, 1916 The precautions taken to meet the demands of the experiments are not discussed in detail because they have already been given in previous papers. The frog tadpoles (when they can be used) are in all respects more suitable than salamander larvae. When collected late in the fall they can be kept at a fairly constant size and the results obtained under these conditions are not complicated with growth phenomena. They have proved to be remarkably uniform in several series. The salamander larvae on the other hand vary in rate of regeneration from day to day. The factors involved in this fluctuation were not discovered and could not be remedied but may be related in some way to the fact that these animals require living active food and the feeding reactions are therefore more complicated than in frog tadpoles and more subject to disturbance. In regard to certain factors, such as the degree of injury, in which expected differences in rate are slight the writer has felt that he might be biased in making the measurements and in a number of. Cases this work was therefore delegated to a person who had -no preconceptions concerning the result. In making averages elimination of individual cases is avoided except for a few very aberrant values. Such exceptional values are in every case however included in the tables. In many cases where only slight differences are to be expected several different kinds of comparisons are made so as to bring out the correct relation as completely as possible. As in the past all data obtained by the writer on the particular factors in question are given. The practice of selective elimination would be dangerous because of the large value of factors not at present under experimental control. 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.