DEDICATED 



WITH GEATITUDE AND BESPECT 

 TO 



SIE JOSEPH DALTON HOOKEB 



G.O.S.I., O.B., M.D., F.B.S., D.C.L., LL.D., &o. 



THEOUGH WHOSE KIND ENCOUBAGEMENT 



THIS MONOGBAPH 

 HAS BEEN PUBLISHED 



