SPONGES 



sponge are so subtle that only a lifelong study of 

 them can distinguish one from another. The wool 

 sponge is whiter than the others; the yellow is 

 yellower. The little reef sponges used for toilet 

 and surgical purposes are conspicuously different 

 from the rest; but though the grass sponge is 

 apt to grow in fantastic shapes more often than 

 others, it is not an infallible means of recognising 

 it, as almost any of them may rival it in eccen- 

 tricity on occasion. 



The purple or yellow cup sponges are curious. 

 They are found attached to the rocks by a thick 

 stalk "Venus cups," the largest variety is some- 

 times called which is often eighteen inches high 

 and occasionally very much larger. 



Then there are thick fingers of brilliant scarlet 

 or crimson. These are the finger sponge, or when 

 tubular are called the organ sponge, from their re- 

 semblance to organ pipes. Similar to these are 

 others of a delicate violet colour. Still another 

 species is a deep oily crimson which looks nearly 

 black in the water ; the colour can be used to dye 

 cloth and can be squeezed out in a few minutes. 

 The sour sop sponge is green or yellow and is of 

 several varieties. In texture it is soft, and tears 

 easily. It cannot be used for anything nor satis- 

 factorily preserved except in formalin. 



The finger sponge should be found within the 

 glove sponge, but it isn't. It grows in long, nar- 



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