ON SHELL-FISHES AND CUTTLEFISHES. 19 



supply — is evidence that the ways of nature are full of purpose 

 though they may not always be understood. i 



Man's influence over the preceding mollusks is limited to 

 the inshore, and especially the tidal mussel, cockle, clam, and 

 oyster-beds, to the periwinkle, limpet, and ear-shell between 

 tide-marks, and there it ceases. Even were he to destroy every 

 mussel, cockle, clam, and oyster-bed within his reach, the gaps 

 would be filled up by forms (including those mentioned) beyond 

 his power, and the wealth of molluscan life maintained to 

 succeeding generations. The operations of nature elsewhere 

 are on too vast a scale for his interference. By a single storm 

 she teaches him the inefficiency of dredge, trawl and net, and 

 strews the beach with myriads of shell-fishes of every size, few 

 or none of which are ever disturbed by his operations, \and 

 which prove a valuable harvest of bait to the fishermen, and 

 perhaps bring many a predatory food-fish inshore in search of 

 the easily captured spoil. More powerful than the "gribble," 

 the boring shell-fishes (Xylophaga and Teredo) tunnel their 

 way in submerged timber of all kinds and rapidly disintegrate 

 the masses of wood borne to the sea by great rivers. Man can 

 neither arrest their ravages in unprotected wood throughout 

 the ocean, nor utilize their labours as he desires. 



From early times, again, cuttlefishes have been used as food 

 by man, and still more extensively by the larger fishes, such as 

 the bonito, as well as by the whales. No delicacy was valued 

 more highly amongst the ancients on the eastern shores of the 

 Mediterranean than these mollusks. In modern times they 

 have been eagerly sought for bait and so highly prized that as 

 many as possible are captured for this purpose, both on our 

 own and other shores. Some whales, such as the Sperm-whale 

 (Fig. p. 20), live to a large extent on them, so that w^hen this 

 species was more common than it is now the annual consump- 

 tion must have been great \ The majority of the cuttlefishes 

 are, however, pelagic in their adult state, and the young of 



^ It has happened that a sum of £5 or even £10 has been given for a single 

 box of cuttlefishes as bait. The cost of a year's consumption in the case of this 

 whale must be enormous. 



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