viii PREFACE TO THE FIRST EDITION 



included on account of their own importance and that of the 

 pathological processes which they illustrate. 



Our best thanks are due to Professor Greenfield for his kind 

 advice in connection with certain parts of the work. We have 

 also great pleasure in acknowledging our indebtedness to 

 Dr. Patrick Manson, who kindly lent us the negatives or pre- 

 parations from which Figs. 174-179 have been executed. 



As we are convinced that to any one engaged in practical 

 study, photographs and photomicrographs supply the most useful 

 and exact information, we have used these almost exclusively in 

 illustration of the systematic description. These have been 

 executed in the Pathological Laboratory of the University of 

 Edinburgh by Mr. Richard Muir. The line drawings were 

 prepared for us by Mr. Alfred Robinson, of the University 

 Museum, Oxford. 



To the volume is appended a short Bibliography, which, 

 while having no pretension to completeness, will, we hope, be of 

 use in putting those who desire further information on the track 

 of the principal papers which have been published on each of 

 the subjects considered. 



June 1897. 



