Molhisoa. 77 



foremost (Fig-. 73). The arms are used for crawling- and climbing-, they 

 serve also to catch and hold the prey witli their suckta-s. Food consists 

 chiefly of crabs wiiicli, after being- caught and cjuried to thenionth hynieans 

 of the arms, are quickly paralyzed by a poisonous fluid secreted by the 

 salivary glands. Then tiic juices are sucked out of the 1)ody, the solid 

 parts not being- swallowed. Tiie Octopus are strong- and daring- robbers, 

 lying in wait for tiieir prey in the crevices of the rocks. In the Aquariiim 

 they pile up largo stones into a lieap beliind wliich they conceal themselves, 

 ready to pounce out on the unwary fislies; their power of ciianging- their 

 colour and of producing- all sorts of warts and wrinkles on their other- 

 wise smootii skin, enables them to countt-rfciL so closely their surroun- 

 dings, that they can only be disting-uished with difficulty. They are 

 caught all round the coast of tlie Mediterranean, allured by baits, upon 

 which they pounce and with wliich they arc liauledup. They are found 

 in all Neapolitan flsii markets, as they are often eaten, and the arms of 

 young- specimens are especially esteemed. 



A very near ally of Octopus is Eledone mosehata, the Musk- 

 octopus, much smaller and witii only one row of suckers on each arm. 

 They arc very shy and try to hide themselves from view. When taken 

 out of the water tliey give out a strong- odour of musk. As they are 

 frequent in occixrrence they are often brought to market, but are gene- 

 rally only eaten by tlie conniion people. 



( )ne of the most interesting and most important of the Cephalopods 

 is the Sepia or Cuttlefish (Sepia officinalis. Fig-. 78). Their body is 

 oval, somewhat flattened, and with a membranous fin running- down both 

 sides. Beneath the dorsal skin is the « cuttle-bone », found often on tlie 

 English coast and given to captive canaries to sharpen their beaks. 

 The eight arms are much shorter than those of the Octopus and are 

 generally carried closely applied together ; between tiiem is hidden an- 

 other much longer pair of arms which can be shot out to catch crabs 

 or fish. 



The most noticeable characters in Sepia are the excretion of an 

 inky fluid and the change of colouring in the skin. Both of these they 

 have in common with the other Cephalopods, but they make more fre- 

 quent use of them. The sepia used by artists is the product of a gland, 

 the so-called ink-sack, the contents of which can be squirted out through 

 the funnel 5 a small quantity is enough to suddenly envelope the animal 

 in a black cloud, which hides it from its pursuer. The ink is extracted, 

 dried and brought to market; even that of fossil species can still be used. 



— Tiie wonderful play of. colours on the living- animal is due to large 

 cells (chromatophores) which are situated in the skin and are filled with 

 finely divided dark colouring- matter; as these cells contract (become glo- 

 bular) and expand (become fiat), a continuous change of colours takes 

 place; stripes, spots and markings make their appearance and disappear 

 according as the animal is at rest or is irritated. The Cuttlefish have 

 complete control over tiiis change of colours; this is seen from the 

 protective colouring, which they assume when they lie on the sand or 

 on dark rocky ground; in cither case they can hardly be distinguished. 



— The males court tlie females with g-reat anlnur, and in their excited 



