TO 
JOHN KIDD, M.D., F.R.S. 
REGIUS PROFESSOR OF MEDICINE IN THE UNIVERSITY OF OXFORD, 
&e. &e. 
TO WHOSE 
ZEALOUS SUPERINTENDENCE AND DISCRIMINATING TASTE 
THE RADCLIFFE LIBRARY 
OWES MUCH OF ITS PERFECTION AS A TREASURY 
OF NATURAL HISTORY, 
Chis Book, 
PRINCIPALLY WRITTEN WITHIN ITS WALLS, 
IS RESPECTFULLY DEDICATED BY 
THE AUTHOR. 
