PREFACE TO THE EIGHTH EDITION. 



Since the last edition of this work appeared, in 1893, many 

 important discoveries have been made in Pathological and 

 Biological Science, more particularly in the departments that 

 treat of the evolution, the physiological or pathological effects, 

 and all tlie various phenomena associated with the develop- 

 ment and life -history of the lower forms of life known as 

 Bacilli, Bacteria, and Microbes. The Author has therefore 

 been compelled to completely recast the Bacteriological portions 

 of his work. 



In 1882 an attempt was made by certain parties to disparage 

 and minimise the importance of a discovery which the Author 

 claimed to have made, namely, the organism of the Tick. 

 Since then the Author has continued assiduously his investiga- 

 tions, with the result that his former conclusions have been 

 abundantly confirmed. For further information on this point, 

 he refers the reader to the chapter on what is popularly termed 

 Louping-Ill, which he has ventured to term Ixodic Toxaemia. 

 This chapter, along with that on Texas Fever (termed by the 

 Author Ixodic Antemia), which he had special opportunities of 

 studying while in Jamaica in the summer of 1896, will, he 

 trusts, be found interesting as being founded on the theory that 

 certain saprophyte filaments, innocuous in themselves, may, 

 when ingested with foods which they infest, become pathogenic 



