LONDON
T. FISHER UNWIN
PATERNOSTER SQUARE
MDCCCXCVII
Copyright by T. Fisher Unwin, 1897, for Great Britain
and Longmans Green & Co. for the
United States of America
To
DR. PHILIP HENRY PYE-SMITH, F.R.S.
IN RECOGNITION OF HIS PROFOUND KNOWLEDGE OF
THE PRINCIPLES ADVOCATED BY HARVEY, AND
IN GRATITUDE FOR MANY KINDNESSES
CONFERRED BY HIM UPON
THE AUTHOR