Vlll PREFACE 



Among the difficulties which confront the teacher of comparative 

 anatomy is the reluctance of students to acquire a vocabulary of technical 

 terms. As far as possible in this text familiar, non-technical language is 

 used. Unfortunately, it is impossible to eliminate technical terms wholly 

 from an anatomical text. In defense of their use it should be emphasized 

 that they avoid much circumlocution and thus make for brevity. 



This book is not intended to be used as a laboratory manual but as a 

 text to supplement, interpret, and integrate the facts acquired in the 

 laboratory. The foundations of a course in comparative anatomy should 

 be laid in the laboratory so that the student may have first-hand acquaint- 

 ance with at least a fish and a mammal — and if possible a tailed amphibian 

 also. For such laboratory work a suitable laboratory manual should be 

 used. Since this text deals comparatively with each of the various organ 

 systems in turn, a laboratory manual which follows this plan is desirable. 



For some years this text in mimeographed form has had the benefit 

 of student criticism, with the consequent elimination of many obscurities 

 and inconsistences. The typescript copy has been read by Mr. Edwin 

 Tenney Brewster of Andover, Massachusetts, and by Professors A. 

 Brazier Howell and W. L. Straus, Jr. of the Johns Hopkins University. 

 For what these have done to improve the book the authors are deeply 

 grateful. The authors consider themselves most fortunate to have had 

 the efficient services of John Howell Neal who has drawn or redrawn most 

 of the text figures. All new drawings required for the chapters on repro- 

 duction and histology (chapters 2 and 3) were made by Mary B. Marks. 

 Of the text-books in comparative anatomy which have been consulted 

 those of Goodrich, Ihle, Kingsley, Plate, Stempell and Wilder have been 

 especially valuable. For embryological facts and figures, the authors 

 have leaned heavily upon Arey, Corning, Kellicott, MacBride, and Patten. 

 In human anatomy, the text-books of Braus and of Morris have been much 

 used. In histology, Bremer's text, and in neurology, the text-books of 

 Herri ck and of Ranson have been most helpful. 



In this text-book the discussion of each organ or organ-system is 

 divided into three parts — phylogenesis, ontogenesis, and anatomy. 

 Since it may be assumed that the student has first-hand acquaintance 

 with the anatomy of such a mammal as the cat, and since he presumably is 

 more interested in the human species than in any other mammal, anatomi- 

 cal description in this text emphasizes human anatomy. The descriptions 

 of ontogenesis are also mostly based upon the human embryo. If, as 

 the authors believe, the main purpose of a course in comparative anatomy 

 is, to throw light upon the structure of the human body, to ignore it as 

 some text-books do seems like a performance of Hamlet with the Prince 

 left out. 

 Boston, Massachusetts 



