WITH GREAT RESPECT, TO THE MEMORY OP THE LATE 



DR. GEORGE JOHNSTON, 



OP BEBWICK-ON-TWEED, 

 AN ENTHUSIASTIC AND TALENTED OBSERVER AND WRITER ON 



NATURAL HISTORY; 



WHOSE NUMEROUS WORKS ON BOTANY AND MARINE ZOOLOGY, AND ESPECIALLY 



ON THE SPONGES AND ZOOPHYTES OP GREAT BRITAIN, 



HAVE POWERPULLY AIDED IN THE DIPPUSION OF A TASTE POll 



THE CULTIVATION OP THOSE SCIENCES. 



