POLYPES. 



'ETWEEN the class of Worms and that of 

 Polypes there exists many groups of in- 

 ferior animals which, hitherto, have not 

 been employed by man ; such, for instance, 

 are the Medusae (Sea-blubbers and Sea- 

 nettles), and the different varieties of Star-fish 

 (Asteria, Ophiura, etc.) Many of these are men- 

 tioned in my work on Phosphorescence, as most of 

 them evince the faculty of becoming luminous in 

 the dark. Some of these animals have been used as 

 manure on the sea-coast, but with little or no effect. 

 Among the Echinodermata (Star-fish, Ophiura, etc.) 

 there is, however, an animal, Holothuria priapus, or 

 sea-slug, which for years has been exported in large 

 quantities from several of the Malay Islands to China, 

 Cochin China, etc. Hundreds of junks or canoes 

 are paddled along the shallow beaches on the coasts 

 of the East India islands, and filled with these soft 

 gelatinous beings. The Holothuria are purged of 

 impurities by having quick lime thrown over them. 



