32 HOMES UroEK THE SEA. 



wishes to seize upon any object, it presses the rim of the 

 cup firmly against its surface, and withdraws the piston. 

 A vacuum is therefore formed, and the pressure of the 

 atmosphere, combined with that of the water, causes the 

 cup to adhere strongly to the object. This power is 

 increased according to the number anl size of the cups, 

 or suckers. 



So powerful, indeed, is the adhesion that it would be 



THE OCTOPUS. 



easier to tear the sucker from the arm than to loosen its 

 hold. In some of these creatures the adhesive power is 

 increased by a horny claw arising from the centre of the 

 piston. 



Even in the comparatively small specimens which are 

 exhibited in our aquaria, the power of suction is almost 



