PLANTS ON SHIPS' HULLS 



concrete blocks of an esplanade have been shattered to 

 pieces and tossed all over the shore, one may go down to 

 the shore and there will be no visible diiFerence in the kelps 

 and tangles of the rocks. Scarcely any seem to have 

 been broken away. Indeed, if one looks in the rubbish 

 left by the last high tide, one finds that when one of these 

 Alarias has been broken away, it is often because the stone 

 itself has been torn out of the rock ! One finds broken off 

 stones with the seaweed still attached to them. 



The reason is that the outside of the seaweed is oily, 

 slimy, or slippery, so that the water gets no hold of it. The 

 stem and substance is also elastic and surprisingly strong, so 

 that the daily tossing and wrenching when the tides come in 

 and go out has no effect in tearing it away. 



But if you go down to a dry dock and look at the hull 

 of a ship which has come in to be cleaned and scraped, 

 you will see that it is entirely covered by seaweeds and 

 shells. 



That ship has been driven through the water perhaps at ten 

 miles an hour or more, and yet those delicate-looking sea- 

 weeds have held on ! It is more surprising still if you can get 

 some of them and examine them with a microscope, for 

 amongst them are tiny, delicate, graceful little fronds and 

 sprays which one would think consisted of nothing but jelly. 

 Yet they have been able to thrive and grow on the ship's 

 hull while it has been hurrying day and night through the 

 sea, in calm or in tempest, and in currents of hot or cold 

 water. 



Those seaweeds were called by Horace Algae inutiles, 

 or useless seaweeds ; but are they useless ? 



Go down to a little pool and watch them waving in the 

 water. Could anything be more beautiful than these little 



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