THE IMPENETRABLE SEA 



cephalopods use their ink to create a kind of underwater 

 ''smoke-screen" under cover of which the animal escapes 

 its enemies — but this is only a half-truth, or over- 

 simplification of the facts. Cousteau, who has witnessed 

 more cephalopodan ink-discharges than most men, says 

 in describing one of his experiences : "We found that the 

 emission was not a smoke-screen to hide the creature 

 from pursuers. The pigment did not dissipate : it hung in 

 the water as a fairly firm blob with a tail, too small 

 to conceal the octopus. . . . The size and shape of the pufif 

 roughly correspond to that of the swimming octopus 

 which discharged it." 



Frank Lane rightly quotes the suggestion that the 

 octopus or other cephalopod discharges its ink, not as a 

 smoke-screen, but to confuse its attacker by creating a 

 semblance of itself We might take the squid as an 

 instance of what happens. Menaced by the approach of 

 an enemy, the creature suddenly paints a picture of itself in 

 the water — Gousteau's words show that this is no exag- 

 geration — and while its attacker's attention is diverted to 

 a "shadow squid" the squid uses its complicated muscles 

 to close the pigment cells on its body-surface, so that it 

 vanishes from sight and makes oflf, leaving its attacker 

 concentrating on "a fairly firm blob with a tail". 



If necessary the squid can eject "ink forms" several 

 times in succession so that its attacker would be deceived 

 into rushing towards one phantom after another, while 

 the real squid, at a safe distance, quickly assumed its 

 normal appearance. 



Eels are much excited by the presence of sepia in the 

 water. They dash wildly about seeking their ancient 

 enemy. Denis L. Fox, the American biologist, once 

 ofifered a moray eel, that he had in a tank, a mussel 

 removed from its shell. The eel refused it, but when 

 Fox dipped it in some octopus ink it was greedily 

 swallowed. 



Two other experimenters — the MacGinities — put a 



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