PREFACE. 



Vertebrate anatomy is everywhere taught by the laboratory method. 

 The student studies and dissects representatives of several classes, thus 

 gaining an autoptic knowledge of the various organs and their positions 

 in these forms. These facts do not constitute a science until they are 

 properly compared and correlated with each other and with the condi- 

 tions in other animals. It is the purpose of the author to present a 

 volume of moderate size which may serve as a framework around which 

 these facts can be grouped so that their bearings may be readily recog- 

 nized and a broad conception of vertebrate structure may be obtained. 



In order that this may be realized, embryology is made the basis, 

 the various structures being traced from the undifferentiated egg into 

 the adult condition. This renders it easy to compare the embryonic 

 stages of the higher vertebrates with the adults of the lower and to 

 recognize the resemblances and differences between organs in the 

 separate classes. There has been no attempt to describe the structure 

 of any species in detail, but rather to outline the general morphology 

 of all vertebrates. To aid in the discrimination of the broader features 

 and the more minor details, two sizes of type have been used, the 

 larger for matter to be mastered by the student, the smaller for details 

 and modifications in the separate classes to which reference may need 

 to be made. 



Considerable space has been given to the skull, as there is no 

 feature of vertebrate anatomy which lends itself more readily to 

 comparative study of the greatest value to the beginning student, 

 while the same specimens can be used in the laboratory year after year. 

 The skull also has a special interest since nowhere else is there the same 

 chance of tracing modifications in all groups since the first appearance 

 of vertebrates on the earth. To aid in this, extinct as well as recent 

 species have been included. 



It was the desire of the author to adopt the nomenclature of the 

 German Anatomical Society ('BNA'), but this was often found im- 

 practicable. The BNA was based solely upon human anatomy and 

 it fails utterly in many respects when the attempt is made to transfer 

 its terms to other groups. The single example of ' transverse process' 



