VI 



Preface 



For purely pedagogical reasons, the develop- 

 ment of the chick has been described by 

 periods ; that is, all the changes that take place 

 during a certain period are described in one 

 section, instead of describing at one time, the 

 complete development of any one organ. 



The author does not lay claim to any great 

 originality in the compilation of this volume. 

 He has sought simply to collect, into conven- 

 ient form, the more important facts of the sub- 

 ject under discussion, together with a series of 

 figures that will suitably illustrate these facts. 



Marshall and Morgan have been quoted at 

 length, in several instances. 



Nearly all the figures have been taken from 

 well-known text-books of embryology, the au- 

 thor being stated in every case. 



I am especially indebted to Dr. Charles S. 

 Minot and his publishers, P. Blakiston's Son 

 & Co., for the loan of the electros of the numer- 

 ous figures that have been taken from Professor 

 Minot's recent Laboratory Text of Embryology. 



Albert M. Reese, 



Syracuse University, 

 March /jr, igo^. 



