INTRODUCTION 



THE following pages give a brief synopsis of that 

 part of the course in General Biology in Princeton 

 University which deals with the General Morphology of 

 Animals; other parts of that course are General Physiology, 

 Ecology and Biogeny (Genetics and Evolution). The Gen- 

 eral Morphology is printed in this form because of the 

 difficulty of finding elsewhere any such brief summary and 

 because of the repeated requests of students for such a 

 syllabus. In general the whole subject of animal morphology 

 is here dealt with from the genetical (embryological and 

 evolutionary) point of view because it is easier to under- 

 stand complicated structures when they are seen in the 

 process of becoming and also because by this method fun- 

 damental resemblances or homologies are more readily ap- 

 preciated. In so brief a statement covering so wide a field 

 only bare outlines can be given ; very much has been omitted 

 and many statements which should have been qualified have 

 been given baldly, but it has seemed best in an elementary 

 course to present only the leading principles, processes and 

 structures of animal morphology without confusing the be- 

 ginner with a multitude of details or with many qualifica- 

 tions or exceptions. It is expected, of course, that students 

 will use this synopsis only in connection with lectures, labo- 

 ratory work, and assigned readings. 



