PREFACE 



THIS small volume is the result of a need 

 that the author has felt, for some years, 

 for a concise text-book of embryology 

 that described the development of both the 

 chick and the frog. The only other single 

 book, with which the author is acquainted, 

 that describes the development of both these 

 commonly studied forms is the large volume of 

 Marshall, which is too cumbersome and expen- 

 sive for a general, class text-book. 



The present volume is intended as an out- 

 line, from which the student may learn the 

 main facts about the embryology of the two 

 animals in question ; and the instructor is sup- 

 posed in his lectures to enlarge upon this out- 

 line to any extent that he may see fit. Since 

 the needs of the medical student have been 

 largely considered in compiling the text, very 

 little space has been given to theoretical dis- 

 cussions ; these may be given by the instructor, 

 at whatever length may seem desirable. 



