PKOFESSOK JOSEPH LEIDY, M. D., LL. D., 



PRESIDENT OF TUE AOADEMT OF NATITBAL 8CIEITGE8 OF FHILADELPHIA, AC^ 



WHOSE PROFOUND EESEARCHES HAVE SO LARGELY TENDED TO DEVELOP 



THE SCIENCE OF BIOLOGT, 



THIS VOLUME IS RESPECTFULLY DEDICATED. 



A. H. 



