Preface 



New textbooks are usually viewed as revisions of those that pre- 

 ceded them — although they may be abridgments or expansions. It 

 would be presumptive to propose to present comparative mor- 

 phology in an entirely new way; yet there should be some justi- 

 fication for another text. Justification is based on the answers to 

 several questions: Do current texts document, in terms of actual 

 observed structures, and phylogenetic history they describe or do 

 they demand acceptance of an authoritative view? Do current texts 

 serve as an introduction to research in this area, so that the stu- 

 dent can read with comprehension the current literature? 



With such questions in mind, it was apparent that what was 

 needed was a text enriched in vocabulary and concept, both in 

 terms of anatomy and of systematics. The text should in some ways 

 be a report on current research. It should demonstrate the method 

 of approach and present a transection of existing views on the 

 many facets of structural history. Although the whole of compara- 

 tive morphology cannot be reviewed in a single volume, a prac- 

 tical sample can. It was with this in mind that this volume was 

 planned. 



As a part of this fresh approach, many of the illustrations are 

 originals, drawn by the author from his dissections. Like the illus- 

 trations, many of the basic facts have been personally investi- 

 gated. However, there is still a vast debt to the previous works in 

 this field. In the selection of descriptive materials, discussion is 

 restricted to as few kinds of animals as possible. Ranging over the 

 entire chordate series would only have resulted in a presentation 

 of anatomical vignettes. In each account, or chapter, a balance 

 has been sought between a knowledge of facts and an understand- 

 ing of their phylogenetic contribution. Each chapter looks at the 

 whole area concerned rather than at a few spotlighted parts of it, 

 which is usually done because of presumed practicality or student 

 interest. 



