CONTENTS. XIX 



CHAPTER XL 



SPONGES. 



Bemarks on Classification Structure of a Sponge Natu- 

 ralists who have contributed to the History of Sponges 

 Chemical Nature of Sponge Interesting results 

 Spongia officinalis and S. usta The Syrian toilet 

 Sponge Its high price Other Sponges Objects for 

 the Aquarium Spongilla fluviatilis and S, lacustris, or 

 the Fresh-water Sponges Sponges common on the 

 English Coasts Their use in Medicine Sources of 

 Iodine and Bromine Flints and Agates as owing their 

 formation to Sponges Petrified Sponges Practical 

 details on the Toilet Sponge Sponge Fishery and 

 Markets 265282 



