IV PREFACE TO THE TWELFTH EDITION. 



In the preparation of the present edition it seems only right to 

 state, that while I am responsible with my colleague, Dr. Yincent D. 

 Harris, for the general supervision of the work in its passage through 

 the press, he has undertaken the labor of investigation and the arrange- 

 ment of the details. Many parts, moreover, he has re-written. 



And to him has fallen in chief part the difficult task of selecting 

 from the many new facts and observations which have been published 

 within the last few years such as can fitly find a place in a handbook 

 for students. 



W. MORRANT BAKER. 



September, 1888. 



