THE FRIEND OF THE PINNA. 63 



of this natural cordage. Reaumur states also, that the 

 marine mussels are able to form these threads from 

 the earliest periods of their existence ; for he saw 

 them practising this art when their shells were not 

 larger than a millet seed. 



Poli says, with respect to the byssus of mussels, 

 which have all of them this power, that it is of the 

 same structure with hair, and that, at the extremities, 

 it is furnished with little cups or suckers, by which it 

 adheres so firmly, that the mussels can only be drawn 

 from the water in great bunches. Some species are 

 entirely enveloped with this substance. 



The shell of the pinna ingens is said to be often 

 two feet long, and the threads are scarcely inferior in 

 beauty and fineness to those of the silk-worm. Sepa- 

 rately, they possess but little strength ; but their great 

 number is sufiicient to secure the creature in a fixed 

 situation. 



The cuttle-fish is the enemy of the pinna ; but she has 

 a friend in a little crab which lives in her shell, and as 

 an old writer says, " Pays her a good price for his lodg- 

 ing." The crab has red eyes, and sees very sharply ; 

 and whenever he observes the foe at hand, he gives a 

 warning, which is attended to at once. Dr. Walsh, 

 chaplain to Viscount Strangford, when he was our 



