PREFACE, 



In treating a subject so new, and to a great extent so 

 obscure, as the ' History of the Spongiadae,' it may reason- 

 ably be deemed necessary that the author should explain to 

 his readers the origin and object of the work which he 

 presents to them. 



The highly interesting and valuable researches of Pro- 

 fessor Grant in the unexplored field of their anatomy and 

 physiology published in the ' Wernerian Memoirs,' and in 

 the ' Edinburgh New Philosophical Journal,' and the labours 

 of Dr. Johnston, in collecting and identifying the species 

 described by numerous authors, ably concluded and pub- 

 hshed in his ' History of British Sponges,' in 1843, natu- 

 rally created an interest in these singular creatures that had 

 never before been excited to so great an extent, and which 

 led naturalists to believe that a new and pleasing field of 

 investigation lay before them. 



Impressed with these ideas, I made some desultory 



b 



