THE HORSESHOE CRAB 



as it has been known to measure seven and 

 a half feet across the disk, and to have tenta- 

 cles more than one hundred feet long. These 

 same Medusa-like tentacles are to be avoided 

 like the Gorgon's locks, for they are plenti- 

 fully supplied with lasso-cells, which sting the 

 naked skin as with nettles. 



Among the collections of delicate and grace- 

 ful seaweeds that are carefully spread out and 

 dried by the amateur, one often finds beauti- 

 ful silvery, branching specimens, which are in 

 reality not seaweeds at all, but hydroids, hum- 

 ble relatives of the jellyfishes we have just 

 been considering. On close examination one 

 sees a multitude of little horny caps attached 

 to these plant-like stems. They are great col- 

 onies of animals living together, and are not 

 far removed from the corals. 



A still more lowly group of animals, several 

 of whose representatives are thrown up on the 

 beach, is the group of sponges often consid- 

 ered plants, but which the great Aristotle 

 rightly contended were animals. These north- 

 ern sponges are, however, lacking in the elas- 

 tic qualities which make the sponge of com- 

 merce so valuable, for, when dry, they are 

 brittle and easily pressed to powder. The 



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