TO 



PROFESSOR JOSEPH LEIDY, M. D., LL. D., 



PKE8IDKXT OF THE ACADEMY OP NATUEAL SCIENCES OP PHILADELPHIA, AC, 



WHOSE PROFOUND RESEASCHES HATE SO LAEGELT TENDED TO DEVELOP 



THE BOIENOE OF BIOLOGY, 



THIS TOLCME IS RESPECTFULLY DEDICATED. 



A. H. 



