CUTTLES. 233 



immediately, and with considerable force, ejects a stream of 

 water through its syphon from the branchial chamber, and by 

 the recoil is sent backward through the water. As it does so 

 we can see the play of colour over its body, showing that the 

 pigment-cells are ever ready to accommodate themselves to 

 the surroundings, that the Cuttle's skin may imitate them. It 

 is not very likely to discharge its inky cloud, for Octopus 

 vulgaris is not so ready as other species to empty its ink-bag, 

 and the ink is of a thicker, less soluble nature. 



The principal food of the Octopus appears to be the smaller 

 Crustacea, and their hunting period after sunset. This is the 

 reason why so common an animal is so little seen. The shell 

 is represented in the Octopus by two short rods of shelly 

 matter embedded in the mantle. The body is like a round- 

 bottomed bag, there being no side expansions (so-called fins], 

 and the arms are connected by a web at their base, the 

 suckers in two rows. The eyes fixed and staring. 



Much more in evidence as a shore animal is the Sepia, the 

 true Cuttle (Sepia officinalis], which lives in shallow water, 

 and whose egg-clusters and broad internal shell we frequently 

 encounter on the beach. The Octopus has but eight arms all 

 told ; the Sepia is adorned with other two, but these are differ- 

 ent from the eight, and may be more correctly distinguished 

 as tentacles. They are much longer than the Sepia's body, 

 very narrow, and without suckers, except near their free ends, 

 where they expand considerably. The outline of the body, 

 apart from the head and arms, is like that of a shield with 

 pointed base. There are narrow expansions right along the 

 sides, serving as fins, the suckers are stalked, and the large 

 eyes are moveable in their sockets. There are four rows of 

 suckers on each arm, and the arms are short. The shell is the 

 familiar " Cuttle-bone " sold by bird dealers, to provide im- 

 prisoned songsters with the necessary lime, and by chemists 

 to be pounded and used as a dentifrice. These shells are 

 familiar to all, and need not be described. They are exceed- 



