CHAPTER X. 



COLLECTING MARINE INVERTEBRATES. 



SPONGES. A live sponge is simply a vast colony of protozoan 

 animals, each member of which lives an independent existence, 

 but all are at the same time mutually dependent upon each 

 other. The sponge of commerce, and the " cleaned " sponge of 

 the museum collection is, like a branch of coral, merely the 

 skeleton of the living aggregation. A live sponge is a dark- 

 colored, heavy, tough gelatinous mass, cold and clammy to 

 handle, quickly offensive if left in the open air, and utterly use- 

 less until " cleaned," or rid of its mass of animal matter. The 

 skeleton of a sponge may be horny, like that of the useful 

 sponges of commerce ; siUcious, like the marvellously beautiful 

 framework of the famous glass spongo of the Philippine 

 Islands (EuplecteUa) ; or calcareous, like the curious little Gran- 

 tia, which looks like a miniature bouquet-holder, with a frill of 

 spines around its open end. 



Owing to the extreme scarcity of sponge collections, very few 

 persons know how great a variety of forms, and what really re- 

 markable forms, exist no farther from home than the waters that 

 wash the coast of our own beloved Florida. I once had the 

 pleasure of collecting no fewer than sixteen distinct species on 

 the beach between Biscayne Bay and New River Inlet, some of 

 them of remarkable form, and all of them nicely cleaned for me 

 by old Ocean. 



Of course, I searched for sponges, and found many a fine spe- 

 cimen buried almost out of sight in the sand, but what glori- 

 ous fun it was, to be sure ! There I obtained the large, coarse 

 "basket sponge" (Hircina campana}, a hollow, inverted cone, 

 often capable of holding a pailful of water; the remarkable 

 finger sponge (Tuba vaginalis), which forms clusters of upright, 



