Excerpt from A Laboratory Manual of Zoology Since the conditions under which laboratory work is done vary exceedingly, it is impossible to outline a course which will be equally acceptable to all teachers. This little book, therefore, presents more forms than any teacher will be likely to want, in the hope that from among them a selection may be made that is fairly satisfactory. The frog is taken up first among the vertebrates, and very fully, so that, if preferred, it may be used as an introductory study instead of the crawfish. In this case, however, the pupil will need the teacher's help in answering a few questions referring to work in the earlier part of the book. In the opinion of the author the crawfish is much the best form that can be used for such a study, since it is remarkably well adapted to bring out many fundamental ideas, while being less specialized in its organs than either frog or grasshopper, and standing more nearly midway between the highest and the lowest forms. The studies in experimental chemistry and physiology which follow this are to be used at the discretion of the teacher in those classes where no work has been done along this line in connection with human physiology. The experiments may be given as demonstrations by the teacher, or the simpler ones may be assigned to pupils for performance before the class. 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.