THE SEA URCHIN 113 



of little sucker-feet, which they poke out through 

 tiny holes in their shells when they are required 

 for use, just as the starfishes do. Well, when 

 they want to disguise themselves, they just push 

 out two or three hundred of these slender sucker- 

 feet between their spines, and take firm hold 

 with them of any small objects that may be lying 

 within reach. In this manner they soon succeed 

 in covering themselves all over, and you might 

 easily look at one of them as it lay at the bottom 

 of a rock-pool without recognising it at all. 



