PREFACE. 



HE contents of this little volume first appeared in the PROVINCIAL 

 MEDICAL JOURNAL during the years 1887 and 1888, under the 

 title of " From Generation to Generation : a Prelude to the Study of 

 Heredity ;" but inasmuch as I found that I had been anticipated in the 

 first part of this heading, I have, for obvious reasons, altered it to the 

 present title, although I still prefer the former as indicating better the 

 character I claim for the work viz., a mere outline of the subject. 



For many years past I have taken much interest in the question of 

 Heredity, and have thus accumulated an immense quantity of information 

 concerning it. The following pages contain the merest outlines of the 

 physiological and psychological aspects of the subject, although I take 

 some credit to myself for making, what I believe to be, the first 

 systematic effort to trace the influence of Heredity in all the main 

 diseases which afflict humanity. 



Wherever possible, I have chosen rather to quote from the greatest 

 authorities, than to detail in my own words the many interesting facts 

 referred to ; thus presenting a picture in which the lights and shadows 

 have been added by the great Masters to the sketch of the Student. 



If I am successful in evolving a deeper lay and professional interest 

 than has hitherto been taken in a subject so intimately concerning the 

 welfare of both classes, I shall be more than repaid for having made 

 the effort. 



27A, Lowndes Street, 



Belgrade Square, S. W. , 



April, 1889. 



