A Laboratory Guide for Beginners in Zoology (Classic Reprint)

Download A Laboratory Guide for Beginners in Zoology (Classic Reprint) PDF Online Free

Author :
Publisher : Forgotten Books
ISBN 13 : 9781528347624
Total Pages : 138 pages
Book Rating : 4.3/5 (476 download)

DOWNLOAD NOW!


Book Synopsis A Laboratory Guide for Beginners in Zoology (Classic Reprint) by : Clarence Moores Weed

Download or read book A Laboratory Guide for Beginners in Zoology (Classic Reprint) written by Clarence Moores Weed and published by Forgotten Books. This book was released on 2017-09-15 with total page 138 pages. Available in PDF, EPUB and Kindle. Book excerpt: Excerpt from A Laboratory Guide for Beginners in Zoology The directions in the introductory chapter are designed to help the teacher in getting material for study; they are not intended for the pupil, although the figures should be helpful in enabling the teacher to show the class what to look for in the case of the microscopic specimens. 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.

A Laboratory Guide for Beginners in Zoology

Download A Laboratory Guide for Beginners in Zoology PDF Online Free

Author :
Publisher :
ISBN 13 :
Total Pages : 144 pages
Book Rating : 4.F/5 ( download)

DOWNLOAD NOW!


Book Synopsis A Laboratory Guide for Beginners in Zoology by : Clarence Moores Weed

Download or read book A Laboratory Guide for Beginners in Zoology written by Clarence Moores Weed and published by . This book was released on 1902 with total page 144 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Animal Structures

Download Animal Structures PDF Online Free

Author :
Publisher : Forgotten Books
ISBN 13 : 9780266593263
Total Pages : 116 pages
Book Rating : 4.5/5 (932 download)

DOWNLOAD NOW!


Book Synopsis Animal Structures by : David Starr Jordan

Download or read book Animal Structures written by David Starr Jordan and published by Forgotten Books. This book was released on 2017-10-22 with total page 116 pages. Available in PDF, EPUB and Kindle. Book excerpt: Excerpt from Animal Structures: A Laboratory Guide in the Teaching of Elementary Zoology The present book is intended to cover the laboratory work in a course in zoology for beginners. In addition a more general idea of animals should be gained from lec tures, from the study of some text-book of zoology, and, above all, from the observation and collection of animals in the fields and streams. 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.

A Laboratory Guide for Beginners in Zoology

Download A Laboratory Guide for Beginners in Zoology PDF Online Free

Author :
Publisher : Forgotten Books
ISBN 13 : 9781330290255
Total Pages : 136 pages
Book Rating : 4.2/5 (92 download)

DOWNLOAD NOW!


Book Synopsis A Laboratory Guide for Beginners in Zoology by : Clarence Moores Weed

Download or read book A Laboratory Guide for Beginners in Zoology written by Clarence Moores Weed and published by Forgotten Books. This book was released on 2015-06-13 with total page 136 pages. Available in PDF, EPUB and Kindle. Book excerpt: Excerpt from A Laboratory Guide for Beginners in Zoology It is generally conceded that a satisfactory course in zoology requires both laboratory study of animal forms and lecture or text-book presentation of the laws of animal life. The teachers most conversant with pedagogical principles also contend that the greatest educational value of the subject lies in the opportunity it gives to furnish the student with an adequate first-hand knowledge of organic evolution. To accomplish this a course in which the pupil begins with the lower forms and works gradually upward is necessary. For the pupil thus follows the development of living things, seeing how each succeeding form is an improvement over the one that went before, and getting some idea of the great laws which govern the growth and sequence of animal life. In his study of these forms of life the pupil needs a guide which shall lead him wisely without telling him too much, and which shall stimulate him to see and to think without bewildering him with questions that he cannot answer. In this little book such an attempt is made. Since the directions were first used in my own classes some ten years ago modifications have been made every year, until in their present form I have found them thoroughly workable with average classes of beginners in zoology. 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.

A Laboratory Guide for Beginners in Zoology

Download A Laboratory Guide for Beginners in Zoology PDF Online Free

Author :
Publisher : Palala Press
ISBN 13 : 9781354691984
Total Pages : 142 pages
Book Rating : 4.6/5 (919 download)

DOWNLOAD NOW!


Book Synopsis A Laboratory Guide for Beginners in Zoology by : Clarence Moores Weed

Download or read book A Laboratory Guide for Beginners in Zoology written by Clarence Moores Weed and published by Palala Press. This book was released on 2016-04-26 with total page 142 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.

LAB GD FOR BEGINNERS IN ZOOLOG

Download LAB GD FOR BEGINNERS IN ZOOLOG PDF Online Free

Author :
Publisher : Wentworth Press
ISBN 13 : 9781374144347
Total Pages : 146 pages
Book Rating : 4.1/5 (443 download)

DOWNLOAD NOW!


Book Synopsis LAB GD FOR BEGINNERS IN ZOOLOG by : Clarence Moores 1864-1947 Weed

Download or read book LAB GD FOR BEGINNERS IN ZOOLOG written by Clarence Moores 1864-1947 Weed and published by Wentworth Press. This book was released on 2016-08-29 with total page 146 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.

A Laboratory Manual of Zoology (Classic Reprint)

Download A Laboratory Manual of Zoology (Classic Reprint) PDF Online Free

Author :
Publisher :
ISBN 13 : 9781330628362
Total Pages : 118 pages
Book Rating : 4.6/5 (283 download)

DOWNLOAD NOW!


Book Synopsis A Laboratory Manual of Zoology (Classic Reprint) by : Margaretta Burnet

Download or read book A Laboratory Manual of Zoology (Classic Reprint) written by Margaretta Burnet and published by . This book was released on 2015-09-27 with total page 118 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.

A Laboratory Manual for Elementary Zoology (Classic Reprint)

Download A Laboratory Manual for Elementary Zoology (Classic Reprint) PDF Online Free

Author :
Publisher : Forgotten Books
ISBN 13 : 9781528149136
Total Pages : 168 pages
Book Rating : 4.1/5 (491 download)

DOWNLOAD NOW!


Book Synopsis A Laboratory Manual for Elementary Zoology (Classic Reprint) by : Libbie Henrietta Hyman

Download or read book A Laboratory Manual for Elementary Zoology (Classic Reprint) written by Libbie Henrietta Hyman and published by Forgotten Books. This book was released on 2017-09-15 with total page 168 pages. Available in PDF, EPUB and Kindle. Book excerpt: Excerpt from A Laboratory Manual for Elementary Zoology Io. Students who declare that they cannot draw will receive little sym pathy. Anyone can make the simple line drawings required in this work. To make a drawing proceed as follows. First determine how large it is to be and select a proper space on the page. Then rule this space with very light vertical and horizontal guide lines so that your drawing will be symmetrical. With a ruler further reduce or enlarge the length or width of the actual Object to fit the space selected. Then with very light lines make an outline of the object; then, constantly referring to the Object, correct this with light lines until the propor tions and details are as nearly like the Object as you can possibly get them. Then erase the light lines until you can barely see them, and go over them making the final lines firm and clear. Every line upon the drawing must represent a structure actually present on the Object. Avoid shading, color, crosshatch ing, etc. 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.

A Guide for Laboratory and Field Work in Zoology

Download A Guide for Laboratory and Field Work in Zoology PDF Online Free

Author :
Publisher : Forgotten Books
ISBN 13 : 9780365127758
Total Pages : 118 pages
Book Rating : 4.1/5 (277 download)

DOWNLOAD NOW!


Book Synopsis A Guide for Laboratory and Field Work in Zoology by : Henry R. Linville

Download or read book A Guide for Laboratory and Field Work in Zoology written by Henry R. Linville and published by Forgotten Books. This book was released on 2018-03-21 with total page 118 pages. Available in PDF, EPUB and Kindle. Book excerpt: Excerpt from A Guide for Laboratory and Field Work in Zoology: For Use in Connection With a Text-Book in General Zoölogy Questions have been arranged both in the form of numbered and unnumbered paragraphs in order that teachers may com pare the two methods; for better comparison the directions for the study of the living locust and the living frog have been printed in both ways. It will be noticed that drawings are required of the pupil after he has studied the animal, and that emphasis is laid on drawings showing the parts in their proper relation in the animal body; in only a few cases, where certain organs cannot be clearly shown in the body, are they to be separated and made the subject of a distinct drawing. 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.

A Laboratory Guide in Elementary Zoology (Classic Reprint)

Download A Laboratory Guide in Elementary Zoology (Classic Reprint) PDF Online Free

Author :
Publisher : Forgotten Books
ISBN 13 : 9780267792405
Total Pages : 82 pages
Book Rating : 4.7/5 (924 download)

DOWNLOAD NOW!


Book Synopsis A Laboratory Guide in Elementary Zoology (Classic Reprint) by : William Fairfield Mercer

Download or read book A Laboratory Guide in Elementary Zoology (Classic Reprint) written by William Fairfield Mercer and published by Forgotten Books. This book was released on 2018-02-04 with total page 82 pages. Available in PDF, EPUB and Kindle. Book excerpt: Excerpt from A Laboratory Guide in Elementary Zoology This is a marine form found abundantly along the New England shores fastened to seaweed, submerged wood, etc., just below low tide mark. Note the difference in size of the specimens submitted for. Examination. Study them with the hand lens. Notethe cylindrical sponge body. Do the two ends differ? Note the opening at one end, the osculum. Press the sponge lightly. Notice the flexibility of the wall. Note the buds on the larger specimens. Do the buds have oscula? Carefully cut a sponge from the osculum to the base. Lay the cut specimen open in water with the cloacal surface up. Does this chamber communi cate with that of the buds? 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.

Exploring Zoology: A Laboratory Guide, Third Edition

Download Exploring Zoology: A Laboratory Guide, Third Edition PDF Online Free

Author :
Publisher : Morton Publishing Company
ISBN 13 : 1640432051
Total Pages : 574 pages
Book Rating : 4.6/5 (44 download)

DOWNLOAD NOW!


Book Synopsis Exploring Zoology: A Laboratory Guide, Third Edition by : David G. Smith

Download or read book Exploring Zoology: A Laboratory Guide, Third Edition written by David G. Smith and published by Morton Publishing Company. This book was released on 2021-01-01 with total page 574 pages. Available in PDF, EPUB and Kindle. Book excerpt: Exploring Zoology: A Laboratory Guide provides a comprehensive, hands-on introduction to the field of zoology. Knowledge of the principal groups of animals is fundamental to understanding the central issues in biology. This full-color lab manual provides a diverse selection of exercises covering the anatomy, physiology, behavior, and ecology of the major invertebrate and vertebrate lineages. Great care has been taken to provide information in an engaging, student-friendly way. The material has been written to be easily adapted for use with any introductory zoology textbook.

Exploring Zoology: A Laboratory Guide

Download Exploring Zoology: A Laboratory Guide PDF Online Free

Author :
Publisher : Morton Publishing Company
ISBN 13 : 161731157X
Total Pages : 577 pages
Book Rating : 4.6/5 (173 download)

DOWNLOAD NOW!


Book Synopsis Exploring Zoology: A Laboratory Guide by : David G. Smith

Download or read book Exploring Zoology: A Laboratory Guide written by David G. Smith and published by Morton Publishing Company. This book was released on 2014-01-01 with total page 577 pages. Available in PDF, EPUB and Kindle. Book excerpt: Exploring Zoology: A Laboratory Guide is designed to provide a comprehensive, hands-on introduction to the field of zoology.Ê This manual provides a diverse series of observational and investigative exercises, delving into the anatomy, behavior, physiology, and ecology of the major invertebrate and vertebrate lineages.

Practical Zoology (Classic Reprint)

Download Practical Zoology (Classic Reprint) PDF Online Free

Author :
Publisher : Forgotten Books
ISBN 13 : 9780331370645
Total Pages : 516 pages
Book Rating : 4.3/5 (76 download)

DOWNLOAD NOW!


Book Synopsis Practical Zoology (Classic Reprint) by : Robert William Hegner

Download or read book Practical Zoology (Classic Reprint) written by Robert William Hegner and published by Forgotten Books. This book was released on 2017-11-18 with total page 516 pages. Available in PDF, EPUB and Kindle. Book excerpt: Excerpt from Practical Zoology Ideas differ considerably as to what constitutes the best course in zoology for secondary schools, but we cannot be far wrong if we succeed in combining a general knowledge of animals and of zoological principles with a discussion of the relations of animals to man, in such a way as to interest the students. The constant references to the relations of animals to their environ ment and the selection of common animals, especially those of economic importance, for illustrative purposes tend to stimulate the natural interest of boys and girls in animal life. 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.

A Laboratory Manual of Invertebrate Zoölogy (Classic Reprint)

Download A Laboratory Manual of Invertebrate Zoölogy (Classic Reprint) PDF Online Free

Author :
Publisher : Forgotten Books
ISBN 13 : 9780266872269
Total Pages : 278 pages
Book Rating : 4.8/5 (722 download)

DOWNLOAD NOW!


Book Synopsis A Laboratory Manual of Invertebrate Zoölogy (Classic Reprint) by : Gilman a Drew

Download or read book A Laboratory Manual of Invertebrate Zoölogy (Classic Reprint) written by Gilman a Drew and published by Forgotten Books. This book was released on 2017-12 with total page 278 pages. Available in PDF, EPUB and Kindle. Book excerpt: Excerpt from A Laboratory Manual of Invertebrate Zoölogy There has been no attempt to make the literature list at all complete, but it seems desirable to refer students to some of the available papers, for by consulting them in connection with their laboratory work they become acquainted with methods of work and develop the spirit of research that is the beginning of real understanding. 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.

Laboratory Guide for Beginners in Zoology

Download Laboratory Guide for Beginners in Zoology PDF Online Free

Author :
Publisher :
ISBN 13 :
Total Pages : pages
Book Rating : 4.:/5 (78 download)

DOWNLOAD NOW!


Book Synopsis Laboratory Guide for Beginners in Zoology by :

Download or read book Laboratory Guide for Beginners in Zoology written by and published by . This book was released on with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Principles of Economic Zoology Field and Laboratory Guide, Vol. 1 (Classic Reprint)

Download Principles of Economic Zoology Field and Laboratory Guide, Vol. 1 (Classic Reprint) PDF Online Free

Author :
Publisher : Forgotten Books
ISBN 13 : 9780365422242
Total Pages : 290 pages
Book Rating : 4.4/5 (222 download)

DOWNLOAD NOW!


Book Synopsis Principles of Economic Zoology Field and Laboratory Guide, Vol. 1 (Classic Reprint) by : Lewis Sylvester Daugherty M. S.

Download or read book Principles of Economic Zoology Field and Laboratory Guide, Vol. 1 (Classic Reprint) written by Lewis Sylvester Daugherty M. S. and published by Forgotten Books. This book was released on 2018-03-23 with total page 290 pages. Available in PDF, EPUB and Kindle. Book excerpt: Excerpt from Principles of Economic Zoology Field and Laboratory Guide, Vol. 1 A satisfactory course in Zoology requires field, laboratory, and text-book work on a series of typical animals. This method will bring the student into contact with the animal world in its manifold relations. The teacher may follow any order which he prefers, but the studies in this guide are arranged With a view to seasonal supply. Insects are plentiful and easily obtained by the class in the fall, while fishes, frogs, and turtles may be kept in aquaria or purchased at any time from dealers in zoologic supplies. Also, the dissection of the vertebrate forms is less unpleasant in the winter. Earthworms and lower forms may be obtained in the spring. Zoology is a study of animals and not information about animals. As Ruskin says, the greatest thing in the world is for a man to see something and to tell clearly what he saw. It is intended that the student find his answers in the animal before him. 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.

A Laboratory Guide in Elementary Zoology

Download A Laboratory Guide in Elementary Zoology PDF Online Free

Author :
Publisher : Forgotten Books
ISBN 13 : 9781330285640
Total Pages : 82 pages
Book Rating : 4.2/5 (856 download)

DOWNLOAD NOW!


Book Synopsis A Laboratory Guide in Elementary Zoology by : William Fairfield Mercer

Download or read book A Laboratory Guide in Elementary Zoology written by William Fairfield Mercer and published by Forgotten Books. This book was released on 2015-06-12 with total page 82 pages. Available in PDF, EPUB and Kindle. Book excerpt: Excerpt from A Laboratory Guide in Elementary Zoology This guide is designed for use in my own classes, and it sets forth an outline of the work done in Zoology. No claim is made as to the originality of the subject matter except in the method of presenting it, and the order in which it is given. It has been in use in our laboratory for several years in mimeographic form. Type forms are taken of the different groups, and carefully studied. The classification of animals conforms to that of the "Manual of Zoology" by Parker and Haswell, which is used as a text for class work. Any other good text may be used. All instructions for the use of apparatus, etc., are left to be supplied by the teacher in charge. Acknowledgment is here due Dr. W. F. Copeland, J. E. McDaniel, Ph. M., and A. A. Johnson, Ph. B., former assistants of mine, and my present assistants, J. A. Badertscher, and C. E. Hayden, for many valuable suggestions in the working of the manual before going to print. 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.