IV PREFACE. 



lias shown that beginners rarely go to the original sources. Tliis 

 omission is the less important since in all schools where the book is 

 likely to be used other works containing good bibliographies are 

 accessible. Reference might here be made to those in the Anat- 

 omies of Lang and AViedersheim, the Embryologies of Balfour, 

 Korschclt and Heider, Minot, and llertwig, and Wilson's work on 

 The Cell. 



The editor must here return his thanks to Dr. Greorge W. l-'ield 

 for his kindness in allowing the use of his translation of the first 

 part of the book as the basis of the present edition. 



J. S. KiNGSLEY. 

 TutTs College, Mass., Sept. 19, 1902. 



